Violent Video Games And Violence Example For Students

Violent Video Games And Violence Recent mass shootings have made the public question the unclear motives of the people behind such destructive behaviour. Unfortunately, many individuals have jumped to rash conclusions regarding the causes of such events by linking violent video games with violence in the youth population. Even more discerning individuals have also criticized the role of violent video games in encouraging people to become mass murderers. With these opinions gaining popularity in the mass media, it has become the predominant belief of society to explain why there are more shootings recently. Such claims are usually driven by opinionated reasoning instead of scientific research, so it is much easier for the popular media to formulate such ostentatious theories. We will write a custom essay on Violent Video Games And Violence specifically for you for only $16.38 $13.9/page Order now This can be seen with professional bloggers, Lyndee Fletcher and Ralph Nader, who are adamant that there is an obvious link between violent video games and the recent mass shootings. As seen in their respective articles published in 2015 and 1999, the controversial opinion on the effects of violent video games have left lasting impressions on the public to believe that frequent exposure has created adolescent mass murderers. This only demonstrates that the predominant belief regarding violent video games and mass shootings over the past two decades is resilient despite the empirical research studies refuting their opinionated claims based. Researchers have tried to establish a scientific basis for understanding in society, but it still has not satisfied the search for the truth behind the mass shooters’ motives and actions. So in order to further understand the link between violent video games and mass shootings, I will further discuss the contrasting opinions of these profess ional bloggers and researchers below. Fletcher was a contributing writer to the movie review blog, Movie Guide, which adopts a Christian perspective to explain the effects of popular media on American youth. She accentuated the idea that video game companies should be held responsible for the actions of recent adolescent mass murderers because they have disregarded the violent consequences (2015). Fletcher reasons this belief by arguing that the adolescents responsible for these events shared three common traits. First, their life revolved around video games because they were addicted. Second, they enjoyed violent video games because it felt familiar and comforting. Third, they all had experience with first-person shooter and massive multiplayer online roleplaying games (MMORPGs), such as Call of Duty and World of Warcraft. So in other words, Fletcher is concluding that these individual’s actions are constructed from frequent violent video game exposure and an increased susceptibility to gaming addiction. In correspondence to Fletcher’s claims, a recent study of 1216 South Korean MMORPG players determined that aggressive and narcissistic personality traits are positively correlated with online gaming addiction, and self-control and interpersonal interaction are negatively correlated to online gaming addiction (Kim et. al, 2007). These variables were of interest because individuals with these characteristics are a part of high risk groups that are more susceptible to addiction of online gaming. In order to determine the relationships between online game addiction and these characteristics, data was collected through questionnaires regarding the participant’s demographic information and game use-related characteristics, in addition to 5-point Likert-type scale assessments regarding online game addiction, aggression, self-control, and narcissistic personality disorder. Through correlational design, Kim’s study suggests that certain characteristics, such as aggression, self-control, and narcissistic personality traits, serve as predictors of online game addiction. That is to say that individuals may be more likely to become addicted to online gaming because they already have these high risk characteristics to begin with, and not because frequent exposure to MMORPGs made these individuals more aggressive and narcissistic, and lack self-control. In addition to this, Kim’s study also suggests that individuals with fewer interpersonal relationships may have a relatively higher dependency on online games because it serves as an alternative to face-to-face interaction and communication for those that feel anxious or stressed socializing. For these reasons, Kim’s disproves Fletcher’s claims that an individual’s actions are constructed in more aggressive ways of thinking through violent video game exposure, because certain individuals have genetic predispositions that make them more susceptible to addiction to MMORPGs which result higher violent video game exposure. .ube5f11b9eeb8f60ff1fc214f78d07091 , .ube5f11b9eeb8f60ff1fc214f78d07091 .postImageUrl , .ube5f11b9eeb8f60ff1fc214f78d07091 .centered-text-area { min-height: 80px; position: relative; } .ube5f11b9eeb8f60ff1fc214f78d07091 , .ube5f11b9eeb8f60ff1fc214f78d07091:hover , .ube5f11b9eeb8f60ff1fc214f78d07091:visited , .ube5f11b9eeb8f60ff1fc214f78d07091:active { border:0!important; } .ube5f11b9eeb8f60ff1fc214f78d07091 .clearfix:after { content: ""; display: table; clear: both; } .ube5f11b9eeb8f60ff1fc214f78d07091 { display: block; transition: background-color 250ms; webkit-transition: background-color 250ms; width: 100%; opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #95A5A6; } .ube5f11b9eeb8f60ff1fc214f78d07091:active , .ube5f11b9eeb8f60ff1fc214f78d07091:hover { opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #2C3E50; } .ube5f11b9eeb8f60ff1fc214f78d07091 .centered-text-area { width: 100%; position: relative ; } .ube5f11b9eeb8f60ff1fc214f78d07091 .ctaText { border-bottom: 0 solid #fff; color: #2980B9; font-size: 16px; font-weight: bold; margin: 0; padding: 0; text-decoration: underline; } .ube5f11b9eeb8f60ff1fc214f78d07091 .postTitle { color: #FFFFFF; font-size: 16px; font-weight: 600; margin: 0; padding: 0; width: 100%; } .ube5f11b9eeb8f60ff1fc214f78d07091 .ctaButton { background-color: #7F8C8D!important; color: #2980B9; border: none; border-radius: 3px; box-shadow: none; font-size: 14px; font-weight: bold; line-height: 26px; moz-border-radius: 3px; text-align: center; text-decoration: none; text-shadow: none; width: 80px; min-height: 80px; background: url(https://artscolumbia.org/wp-content/plugins/intelly-related-posts/assets/images/simple-arrow.png)no-repeat; position: absolute; right: 0; top: 0; } .ube5f11b9eeb8f60ff1fc214f78d07091:hover .ctaButton { background-color: #34495E!important; } .ube5f11b9eeb8f60ff1fc214f78d07091 .centered-text { display: table; height: 80px; padding-left : 18px; top: 0; } .ube5f11b9eeb8f60ff1fc214f78d07091 .ube5f11b9eeb8f60ff1fc214f78d07091-content { display: table-cell; margin: 0; padding: 0; padding-right: 108px; position: relative; vertical-align: middle; width: 100%; } .ube5f11b9eeb8f60ff1fc214f78d07091:after { content: ""; display: block; clear: both; } READ: Essay on Violent Video GamesIn a similar manner to Fletcher, Nader, who is a political activist, also suggests that frequent violent video game exposure increases the likelihood that children will become aggressive and destructive during adolescence because it decreases the children’s awareness to violence and the negative repercussions of violent video games to everyday functioning (1999). Nader references former president Bill Clinton’s meta-analysis of 30 years’ worth of studies, but does not formally introduce the study methods or findings, to demonstrate that this has been an ongoing issue in society. For this reason, he believes that gaming compa nies and parents are to blame because they enable children to become addicted to violent video games through their ignorance and a lack of control. Nader argues this by stating that gaming companies market video games directly to impressionable children by developing more interactive and enticing video games, which according to Nader are of the violent variety, that enable a sustainable addiction and fosters into aggressive and violent behaviour. Contrary to Nader’s beliefs, a recent study of 120 individuals determined that violent video game exposure has no effect on aggression at all (Engelhardt et. al, 2015). This experimental study randomly assigned participants with autism spectrum disorders and participants without autism spectrum disorders to play a video game of either the violent or non-violent variety in order to determine the effects of video games on behaviour. Participants then proceeded to perform post-game rating measures, word completion tasks and competitive reaction time tasks to assess their views regarding the violent content in the video game, aggressive-thought accessibility, aggressive behaviour, and aggressive affect to determine any probable correlation with autism spectrum disorder. The study concluded that violent video game exposure has no effect on individuals with autism spectrum disorder or individuals without autism spectrum disorder, and that video game genre has an effect on the percep tion of violence present in the video game. This suggests aggressive behaviour is not attributable to frequent video game exposure or on a person’s genotype. Therefore, this study disproves the Nader’s claim that violent video games develop aggressive and destructive attitudes during adolescence that influence behaviour because it isn’t attributable to individual differences in behaviour. As shown above, empirical research is an useful approach to understand human behaviour because it provides the opportunity to review information on from a scientific perspective. Paradigms are particularly useful when conducting research as it utilizes underlying theories and assumptions to understand everyday events from a myriad of perspectives. The biopsychosocial paradigm, which is one of many paradigms, suggests that the biological, psychological, and socio-environmental factors interact together to explain certain human behaviours (Davison, 2013). In relation to violence and video games, there are several external factors that may elicit aggressive behaviour in people. Some people may have a genetic predisposition to become more susceptible to video game addiction, personality traits that are prone to exhibit increased aggressiveness, and a lack of familial support. This may result in a coinciding relationship between aggressive adolescents who happen to have frequent exposure to violent video games. Engelhardt’s research study is also based on the preconceived notion that genotypic and phenotypic individual differences may elicit differences in aggressive behaviour, but his study has proven this otherwise by demonstrating that instances of violence are not attributable to these factors. Instead, it is very likely that aggression is related to other confounding variables that may be associated with frequent violent video game exposure. In addition to this, Kim’s research study also expands on the psychological and social factors of the biopsychosocial paradigm suggesting that video game addiction is related to unconscious conflicts within the structure of the mind and interpersonal relationship difficulties. Kim suggests this because those with anxiety and social difficulties are more likely to satisfy needs for social interaction and communication through the means of MMORPGs. So in conjunction with Engelhardt’s biological influence and Kim’s psychological and social influence, these factors may be working in tandem to elicit aggressive behaviour in certain adolescents. In other words, adolescents may be more susceptible to exhibiting violence in the presence of certain biopsychosocial factors that affect behaviour. .ub756973c82345b0a05a91b67bd3f7a6d , .ub756973c82345b0a05a91b67bd3f7a6d .postImageUrl , .ub756973c82345b0a05a91b67bd3f7a6d .centered-text-area { min-height: 80px; position: relative; } .ub756973c82345b0a05a91b67bd3f7a6d , .ub756973c82345b0a05a91b67bd3f7a6d:hover , .ub756973c82345b0a05a91b67bd3f7a6d:visited , .ub756973c82345b0a05a91b67bd3f7a6d:active { border:0!important; } .ub756973c82345b0a05a91b67bd3f7a6d .clearfix:after { content: ""; display: table; clear: both; } .ub756973c82345b0a05a91b67bd3f7a6d { display: block; transition: background-color 250ms; webkit-transition: background-color 250ms; width: 100%; opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #95A5A6; } .ub756973c82345b0a05a91b67bd3f7a6d:active , .ub756973c82345b0a05a91b67bd3f7a6d:hover { opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #2C3E50; } .ub756973c82345b0a05a91b67bd3f7a6d .centered-text-area { width: 100%; position: relative ; } .ub756973c82345b0a05a91b67bd3f7a6d .ctaText { border-bottom: 0 solid #fff; color: #2980B9; font-size: 16px; font-weight: bold; margin: 0; padding: 0; text-decoration: underline; } .ub756973c82345b0a05a91b67bd3f7a6d .postTitle { color: #FFFFFF; font-size: 16px; font-weight: 600; margin: 0; padding: 0; width: 100%; } .ub756973c82345b0a05a91b67bd3f7a6d .ctaButton { background-color: #7F8C8D!important; color: #2980B9; border: none; border-radius: 3px; box-shadow: none; font-size: 14px; font-weight: bold; line-height: 26px; moz-border-radius: 3px; text-align: center; text-decoration: none; text-shadow: none; width: 80px; min-height: 80px; background: url(https://artscolumbia.org/wp-content/plugins/intelly-related-posts/assets/images/simple-arrow.png)no-repeat; position: absolute; right: 0; top: 0; } .ub756973c82345b0a05a91b67bd3f7a6d:hover .ctaButton { background-color: #34495E!important; } .ub756973c82345b0a05a91b67bd3f7a6d .centered-text { display: table; height: 80px; padding-left : 18px; top: 0; } .ub756973c82345b0a05a91b67bd3f7a6d .ub756973c82345b0a05a91b67bd3f7a6d-content { display: table-cell; margin: 0; padding: 0; padding-right: 108px; position: relative; vertical-align: middle; width: 100%; } .ub756973c82345b0a05a91b67bd3f7a6d:after { content: ""; display: block; clear: both; } READ: Violent Video GamesAs researchers have been able to test the validity and reliability of controversial claims, it is important to think critically when confronting opinionated statements about society. Since Fletcher and Nader have used their personal opinions to form rash conclusions, many researchers have acted upon their claims by formally testing it through empirical research. The research conducted by Kim and Engelhardt, for example, has suggested that aggressive behaviour and attitudes are not attributable to violent video game exposure, but rather only associated with it. A multitude of research studies have also reached this conclusion or some variation of it becau se it is very likely that there is no direct causal relationship between violent video games and aggressive behaviour as well. This only demonstrates that by equally valuing social opinion with scientific data, it inhibits our ability to think critically and creatively in the future. So it is important to question phenomena that we encounter on a daily basis to gain a better understanding of human behaviour.

Free Essays on An Ideal Criminal Law Process.

Introduction Criminal law is the prosecution of a person for an act that is classified as a crime, an unacceptable act in the limit of conduct in society. In an ideal criminal law process prosecution for crimes would be swift and just. Certain crimes demand certain punishments and the punishments must fit the crime. In an ideal society, of course there would be no crime. In order for this to happen things would have to change in society. Morality for one, Morality is defined as the principals of right and wrong. Humans as moral creatures deserve praise for good deeds and punishment for bad ones In societies past, punishments were swifter. For example, on September 28, 1953, a young boy was abducted from his school in Kansas City, Missouri. A ransom was demanded and the FBI became involved. The suspects subsequently murdered the young boy on the day of his abduction before the first ransom request was made. This was unbeknownst to the parents and a ransom of $600,000 was paid. On October 6, 1953 the FBI caught the suspects. They appeared before a judge on October 30, 1953, and plead guilty. The jury after hearing the evidence recommended the death penalty after only one hour and eight minutes of deliberation. They were executed on December 18, 1953. (FBI Library) Less than three months after the crime was committed, the punishment was handed out and followed through on. We can learn something from this; the crime was so horrid that the jury had no trouble finding the suspects guilty and to hand down the death penalty. Today that is not usually the case; lawyers try to stack the juries in their favor. To have that one juror to vote his or her way and no matter what the evidence says, that juror will usually vote the opposite of everyone else. A lot of times this is because they feel sorry for the accused. But if the shoe was on the other foot and it was a crime against them they might not feel the same way. To sh... Free Essays on An Ideal Criminal Law Process. Free Essays on An Ideal Criminal Law Process. Introduction Criminal law is the prosecution of a person for an act that is classified as a crime, an unacceptable act in the limit of conduct in society. In an ideal criminal law process prosecution for crimes would be swift and just. Certain crimes demand certain punishments and the punishments must fit the crime. In an ideal society, of course there would be no crime. In order for this to happen things would have to change in society. Morality for one, Morality is defined as the principals of right and wrong. Humans as moral creatures deserve praise for good deeds and punishment for bad ones In societies past, punishments were swifter. For example, on September 28, 1953, a young boy was abducted from his school in Kansas City, Missouri. A ransom was demanded and the FBI became involved. The suspects subsequently murdered the young boy on the day of his abduction before the first ransom request was made. This was unbeknownst to the parents and a ransom of $600,000 was paid. On October 6, 1953 the FBI caught the suspects. They appeared before a judge on October 30, 1953, and plead guilty. The jury after hearing the evidence recommended the death penalty after only one hour and eight minutes of deliberation. They were executed on December 18, 1953. (FBI Library) Less than three months after the crime was committed, the punishment was handed out and followed through on. We can learn something from this; the crime was so horrid that the jury had no trouble finding the suspects guilty and to hand down the death penalty. Today that is not usually the case; lawyers try to stack the juries in their favor. To have that one juror to vote his or her way and no matter what the evidence says, that juror will usually vote the opposite of everyone else. A lot of times this is because they feel sorry for the accused. But if the shoe was on the other foot and it was a crime against them they might not feel the same way. To sh...

Statistical Process Control whilst primarily a manufacturing quality Essay

Statistical Process Control whilst primarily a manufacturing quality technique can be usefully applied in service industries - Essay Example According to above lines, delivery of service is being compared in context to expectation of customers and divergence of expected service quality from delivered quality creates the gap. Ladhari (2009) stated that four characteristics of service like intangibility, heterogeneity, perishability and inseparability make it different from manufacturing offering. . Markovic (2006) argued that manufacturing sector should not be compared with service sector because customers might act as co-producer in service delivery process while customer involvement is negligent in manufacturing process. In such context, Khan (2003) stated that intangibility and inseparability make it difficult to control service quality while there are statistical procedures available to manage quality of manufacturing process. In such context, Chakrabarty and Tan (2007) found that unlike the manufacturing sector, it took time for service sector to realize the importance of Statistical Process Control (SPC) in managing quality. Sulek (2004) argued that most of the common statistical control mechanism can also be used in service sector to manage quality but little bit recalibration of the statistical model is needed in order to utilize it accurate manner in service environment. Discussion Six Sigma & Control Chart Antony (2006) defined the term Sigma as the deviation from service performance characteristics mean while objective of deploying Six Sigma in service sector is to reduce the scope of variation and subsequently improve quality. In order to control variation in the service performance, specific control limit is being assigned (SLupper). Aim of the service performance would be not to cross the upper control limit or the maximum tolerance zone (Yilmaz and Chatterjee, 2000). In case of Six Sigma, distance between SLupper and service process mean is equal to six standard deviations and in this way term â€Å"Six Sigma† has been arrived. In case of six sigma process, deviation in service performance caused by external uncontrollable influences would not exceed the limit of 3.4 parts per million or 3.4 times the service process will show defect out of 1 million times (Antony, 2006). Antony (2006) and Hoerl (2001) stated that Six Sigma process can be applied to service processes like order entry, invoicing, shipping, baggage handling, payroll processing etc. On the other hand, Yilmaz and Chatterjee (2000) measured that defect rate in service sector is less than 3.5 sigma quality level which means 23,000 times the service process will show defect out of 1 million times. In such context, applying Six Sigma as SPC would improve the service performance level to 99.38 per cent. Hoerl and Snee (2002 and 2003) identified benefits of deploying Six Sigma in service sector as 1- decrease in service defect rate which would automatically increase cost efficiency in the service process, 2- management decision would be guided by data driven statistical analysis which would decrease the scope of assumption bases errors and 3- decrease in service defect would significantly decrease customer complaints. Some practical examples can be cited in order to highlight usefulness of Six Sigma model in service sectors. Table 1: Practical Evidences of Implementation of Six Sigma in Service Organizations Organization Benefits J P Morgan Chase (Global Investment Banking) Applying Six Sigma model has helped the company to reduce flaws in service delivery

An Ounce Of Cure By Alice Munro and A Good Man Is Hard To Find by Essay

An Ounce Of Cure By Alice Munro and A Good Man Is Hard To Find by Flannery OConnor - Essay Example The narration is from the third person, but the story is centered on grandmother. She is the one, who is described the most, who’s thought and actions are given more attention. Other characters seems not as important to the story, and others are downplayed so much so that the reader hardly notices they are there, like children’s mother, who seems to wear the same clothes all through the story, she hardly talks, her name is unknown. As to contrast, the grandmother is very particular in her choice of clothing; she is a real â€Å"lady†. However it seems children do not like her so much. The story takes place in Georgia, even though no specific place mentioned. During the second half of the story the characters are mainly in the â€Å"ditch†, only sometime people are taken to the forest. The story keeps the reader in suspense. It starts with an argument in the beginning as to what place they will go for vacation – Florida or Tennessee. The old lady rea lly wants to go to Tennessee, so she uses all the arguments possible to convince her son to head that direction. Then she attempts to talk to her daughter-in-law, but the mother seems to be utterly uninterested in what grandmother has to say.

Debate on Allowing Homosexuals to Adopt Children Essay

Debate on Allowing Homosexuals to Adopt Children - Essay Example This essay highlights that  the debate, in the public view, has less gay rights sympathizers with the majority, under churches and other conservative institutions, being against the idea of gays adopting children. The judiciary, however, has, by requirement, seemingly inclining to the side of favoring the push by LGBTQ since it relies on subjectivity. It does not take into account public opinion. Since empirical data does not suggest conclusively that children raised up by gay couples disadvantages them in their development, the judiciary has made the majority of its rulings to the favor of the LGBTQ. In Legislative bodies, the majority oppose the motion. The debate is however still balanced since such matters demand constitutional changes that require big numbers. The debate will in the Parliamentary context require an overwhelming argument to sway total consensus.From this discussion it is clear that there have been judicial and legislative manifestations of the debate as well as media publicity too. Initially, the Catholic Church and the society, in general, reacted murderously to homosexuality. It was illegal under the law, and one would be convicted for merely confessing love to a person of the same sex. The clerk denied the application and the couple sued him. The trial court sided with the clerk and even after appealing, the appellate court did not find the favor of the couple.

DNA Based Biosensor in Diagnosis: A Review

DNA Based Biosensor in Diagnosis: A Review The advent of fast and easy DNA testing has given the space for the Science to develop small and easy-to-handle equipments called Biosensors. DNA based biosensors have been proven very useful and are accorded with much importance in detecting the target genes responsible for diseases. This article enlists different types of biosensors, their basic principle of operating system, the preparation of DNA microarrays, lab-on-a-chip and their role in diseases diagnosis. DNA biosensors provide swift, sensitive, selective, simple and economical detection of DNA hybridization. New strategies for DNA biosensor are enumerated and are used meticulously in recent trends and for future directions. Carbon nanotubes (CNTs) amplify the electrochemical signal when used with DNA hybridization. Electrochemical, piezoelectric, SPR, optical DNA biosensors are used to detect various viruses like hepatitis virus, HCMV, HIV, orthopox virus etc. and also for the diagnosis of various diseases like cancer, tube rculosis, COPD, genetic diseases (sickle cell anemia i.e. due to single point gene mutation), cystic fibrosis, diabetes etc. The methodologies of detecting such diseases using different types of DNA based biosensors and gene chips are described in this article. PCR free DNA chips, cell- omic sensors and nanosensor are emerging tools in the field of diagnosis. Recent advances in developing such devices provide myriads of new opportunities for DNA diagnostics. Introduction A rapidly developing area of biotechnology arousing intense scientist interest is that of biosensor. Biosensor has become popular in the field of food analysis [1], bioterrorism [3], environmental [2-3] and in the area of human health monitoring and diagnostics [4-6]. Recent advances are being mad in all areas of biosensors technology. Presently, most fascinating and prospective sensors are immunosensors based on affinity reactions between antibody and antigens and DNA biosensors based on the hybridization between DNA probes and their complementary DNA strands. In general, biosensor is an analytical device which employs biological recognition properties for a selective analysis. Such sensors combine a biological element with a physiochemical transducer for the electronic signal output which is proportional to the concentration of analytes [7]. A basic biosensor assembly includes a biological element, transducer and detector. The sensing material may be antibodies, enzymes, whole cell or nucleic acids that form a recognition layer which is integrated with the transducer via immobilization by cross linking, adsorption or covalent binding. Transducers may be amperometric (measuring the current at constant potential) [8], potentiometric (measuring the potential at constant current) [9], piezoelectric (measuring the changes in mass), thermal (measuring the changes in temperature) [10] or optical (detects changes in transmission of light) [11]. The interaction between the analyte and the biological material, used in biosensors may be of two types: a) Bioaffinity sensors: depend on the selective and specific attachment of the target molecule to the surface-attached ligand partner (e.g. antibodies, nucleic acids). b) Biocatalytic sensors: an immobilized enzyme is used as a tool to recognize the target substrate (sensor strips with immobilized glucose oxidase used for personal monitoring of diabetes). A number of steps, much labor, time and costly instruments are required in usual analytical technique whereas biosensors are economical, fast and simple and can be used in small laboratories and hospitals of remote areas which are devoid of sophisticated instruments facilities. DNA Biosensors Nucleic acid recognition process is the basis of DNA Biosensors. These are being developed with a rapid pace with an ambition for inexpensive testing for genetic and infectious disease and for detecting DNA damage and interactions. The study of gene polymorphisms and the analysis of gene sequences play a fundamental role in rapid detection of genetic mutations, opens up new opportunities for reliable diagnosis even before any symptoms of a disease appear. Thus recent advances in developing such devices offer the opportunities for DNA diagnostics. DNA biosensors are made by immobilizing single stranded (ss) DNA probes on different transducers for measuring the hybridization between the DNA probes and their complementary DNA strands [12-13]. The current methods to identify specific DNA sequence in Biological samples depends on the isolation of double stranded (ds) DNA and further polymerase chain reaction (PCR) to amplify the target sequence of DNA. The PCR product is then subjected to electrophoresis or adsorbed onto a suitable membrane and exposed to a solution containing DNA probe. Surface Chemistry and Biochemistry The immobilization of DNA probe onto the transducer plays an important role in the performance of the DNA Biosensor. It should be in well-defined probe orientation and should be readily accessible to the target. The mode of immobilization is the determining factor for the type of environment of probes that are immobilized at the solid surface. On the basis of nature of physical transducer, various schemes can be opted for the DNA probes attachment to the surface such as thiolated DNA utilisation for self binding onto gold transducers, the formation of a complex by the use of biotylated DNA with a surface-confined strepavidin or avidin, covalent binding to the gold surface through functional alkanethiol-based monolayer and coupling covalently (carbodiimide) to the functional groups on carbon electrodes or adsorption onto carbon surfaces. Introduction of peptide nucleic acid (PNA) has paved way for many exciting and new opportunities to DNA biosensors. Peptide Nucleic Acid is a DNA mimic, the only difference is that the sugar-phosphate bone is replaced by a pseudo-peptide one. Like use of surface-confined PNA recognition layers provides remarkable sequence specificity on DNA biosensors and offers other advantages. DNA dendrimers may also be utilized for imparting extreme sensitivity onto DNA Biosensors. By shape, these are tree-like superstructures which possess numerous ss arms that are able to hybridize to their complementary DNA sequence. The immobilization of these dendritic nucleic acids onto physical transducer gives an amplified response [14]. Recent advances in the field of biomolecular techniques may be used to design new generation miniaturized biosensor. Types of DNA based Biosensors 1. Optical Type Fiber optics Biological Element Laser Interferometry Transducer DNA Advantages Optical fiber Highly sensitive Disadvantages Expensive equipment and not portable turbidity interference 2. Electrochemical Type Potentiometric Biological Element Conductometric Transducer Amperometric DNA Advantages Carbon paste electrodes Cheap, Fast Limitations Interference of highly buffered solution 3. Piezoelectric Type DNA Biological Element Quartz Crystals Advantages highly sensitive, Fast 4. DNA chips DNA Quantitative Optical DNA based Biosensor Optical methods are the most commonly used for the detection of analytes. DNA optical biosensors are based on a fiber optic which transduces the emission signal to a fluorescent label and that can carry light from one region to another through a series of internal inflections. The methodology of fiber-optic DNA bio-sensors involves placing of a single stranded DNA probe at the ending-site of fiber and assessing the fluorescent changes resulting from the combination of a fluorescent indicator with the double stranded DNA hybrid [15 16]. The first DNA optical bio-sensors were developed by Krull and Co workers using fluorescent indicator ethidium bromide. A fiber-optic DNA sensor array was developed by Watts group for the detection of multiple DNA sequences at one time [17]. The hybridization of fluorescent labeled complementary oligonucleotides was assessed by observing the increase in fluorescence. A real label free optical detection of DNA hybridization can be offered by a different type of optical transduction based on evanescent wave devices. The different types of optical biosensors include: 1.1 Surface Plasmon Resonance (SPR) It is a quantum optical electrical phenomenon based on the interaction of light with metal surface. Only at specific resonance wavelength of light, the energy carried by photons of light is transferred to packets of electrons (photons) on a metal surface [17]. These biosensors depend on change in surface optical properties (change in resonance angle because of alteration in interfacial refractive index) which results from the surface binding reaction. Thus, these devices integrate the simplicity of SPR with the sensitivity and specificity of wave guiding devices. The SPR signal that is expressed in resonance units is therefore a measure of mass concentration at the senor chip surface [18-20]. 1.2 Molecular Beacons (MBs) MBs are oligonucleotides possessing a stem and loop structure that are labeled with a quencher at one end and a fluorophore on the other end of the stem that converts into fluorescent upon hybridization. MB probes possess high sensitivity and specificity and direct monitoring capability. A biotinylated molecular beacon probe was developed to prepare a DNA sensor using a bridge structure. MB was biotinylated at quencher site of the stem and linked on a glass through streptavidin that act as a bridge between MB and glass matrix. The fluorescence change was measured by confirmation change of MB in the presence of complementary target DNA [21-23]. Quantum Dot It is an ultra sensitive nanosensor based on fluorescence resonance energy transfer (FREET) that can detect very low concentration of DNA. In these neon sensors, quantum dots (QDs) are linked to specific DNA probes to capture target DNA. The target DNA strand binds to a fluorescent dye (Fluorophore) labeled reporter strand and thus forming FREET donor acceptor assembly. Quantum dot also functions as target concentrator as well as FREET energy donor [24]. DNA nanosensor contains two target specific DNA probes i.e. reporter and capture probe. The reporter probe is labeled with fluorophore whereas capture probe is labeled with biotin that binds with streptavidin conjugated with QD [25]. The fluorophore acceptor and QD donor in close proximity produce fluorescence from acceptor by means of FREET on illumination of the donor. The presence of target DNA is indicated by the detection of acceptor emission. The un-hybridized probe does not give fluorescence. The CdSe Zns core shell nanocrys tal can be used as donor and Cy5 (fluorophore) as acceptor for developing QD based DNA nanosensors [25]. For this type of optical bio sensors fluorescent dyes used as standard labels are very expensive and can rapidly photo bleach. An alternate used is chemiluncinscence format, which overcomes the use of fluorescent dyes. A Fiber-optic DNA biosensor array A new method of preparing the fiber-optic DNA biosensor and its array for the simultaneous detection of multiple genes is described. The optical fibers were made into fiber-optic DNA biosensors by adsorbing and immobilizing the oligonucleotide probe on its end but were first treated with poly-l-lysine. The fiber-optic DNA biosensor array was well prepared by assembling the fiber-optic DNA biosensors in a bundle in which each fiber carried a different DNA probe. Hybridization of fluorescent- labeled cDNA of Rb1 gene, N-ras gene and Rb1 p53 gene to the DNA array was monitored CCD camera. A good result was achieved [61]. 2. Electrochemical DNA Bio sensors These are very useful devices for sequence specific biosensing of DNA. The inherent miniaturization of such devices and advance micro fabrication technology make them excellent tool to diagnose DNA. DNA hybridization is detected electrochemically by monitoring the current response at fixed potential. Detection of hybridization is also commonly done through the increased current of a redox indicator or from other changes induced by hybridization in electrochemical parameters such as capacitance or conductivity [26-28]. The discovery of carbon nano tubes (CNTs) plays an important role in development of electrochemical DNA sensors. Various CNT based electrochemical are developed because the combination of unique electrical, thermal, chemical, mechanical and 3-D spatial properties of CNTs with DNA hybridization offers the possibility of creating DNA bio sensors with specificity, simplicity, high sensitivity and multiplexing. Two major groups in which CNTs divided are single walled CNTs (SWCNTs) that are comprised of a single graphite sheet rolled with a tube and multi walled CNTs (MWCNTs) that are concentric closed graphite tubes [29]. CNT enables immobilization of DNA molecules and also used as powerful amplifier to amplify signal transduction of hybridization [30]. Two types are generally used to immobilize the CNT on electrodes aligned and non-aligned. Two approaches are generally used for the immobilization of bio molecules onto CNTs that are non covalent attachment (physical absorption) and covalent binding (some cross linker agents (1-ethyl 3-3 dimethylaminopropyl) carbodilimide hydrochloride (EDC)/N-hydroxysuccinimide (NHS)] or affinity binding (avidin biotin interaction). CNT also act as novel indicator of hybridization. The application of arrayed CNT into DNA chip requires small amount of sample and development of CNT base biosensor has an important role in DNA based diagnostics in hospitals or at home [30]. Various methods are used for immobilizations step i.e. for attaching the DNA probe onto the solid surface that are (a) the use of thiolated DNA probe for self assembled monolayers (SEM) onto gold transducers by covalently bonding to the gold surface through functional alkanethiol based monolayers.(b) Attachment of biotinylated DNA probe through biotin avidin interaction on electrode surface for e.g. avidin modified polyaniline electro chemically deposited onto a Pt disc electrode for direct detection of E. Coli by immobility a 5 biotin labeled probe using a differential pulse Voltametric technique in the presence of methylene blue as an DNA hybridization indicator [31,32]. The electrochemical DNA biosensors may be labeled free and labeled based. Label Free In this direct detection technique the target molecule does not need to be labeled [27]. The elimination of labeling steps simplifies the readout the speed and ease of nucleic acid assays. Thus recently increased attention has been accorded to new label free electrochemical detection schemes. There is a possibility in exploiting the changes in DNAs intrinsic electroactivity (Guanine oxidation peak of hybridization). To deal with the drawbacks of the probe sequences i.e. absence of G, guanines were substituted by inosine residues (pairing with C) and detection of hybridization was done through the target DNA guanine signal. The change in the guanine oxidation and intrinsic DNA redox signals detects the chemical and physical damage [33]. Label Based In label based electrochemical biosensor specific organic dyes, enzymes or metal complexes are used for hybridization detection. Redox active molecules such as methylene blue, dacinomycin that is inserted between the dsDNA and gives signal which is used for detecting hybridization [26] (e.g. of two commercialized DNA chips based on redox active molecules are eSensor TM produced by Motorola life sciences [34], Inc. and Genlyser TM by Toshiba)[35]. Piezoelectric DNA Biosensor These are the mass sensitive devices rely on quartz crystal that oscillate at a defined frequency when oscillation voltage is applied. Increased attention has been given to piezoelectric method due to their simplicity, cost, sensitivity and real time label free detection. The quartz crystal microbalance is an extremely sensitive piezoelectric device that monitors the hybridization events. These biosensors DNA probe is immobilized on the surface of oscillation crystal. The increased mass due to hybridization reaction results in change in oscillating frequency [36-37]. A Piezoelectric sensor for determination of genetically modified soyabean roundup ready [RR soyabean] by immobilizing probe related to 5-enolpyrllvylshikimate 3-phosphate synthase (EPSPS) gene onto gold piezoelectrodes [38]. For detecting a point mutation in a human gene (apolipoprotein-E polymorphism) a combination of DNA piezoelectric biosensor and PCR was developed by immobilizing biotinylated probe on the streptavidin coated gold surface of quartz crystal. The hybridization probes with complementary, non-complementary and mismatched DNA of synthetic as well as amplified PCR samples from human blood DNA was taken out and the device was able to distinguish polymorphism [39]. Colorimetric or Strip type DNA sensor Using these sensors the direct detection of DNA hybridization is possible [40-42]. The dry-reagent strip type biosensor has been developed for visual detection of double stranded DNA within a short time [43]. Oligonucleotides conjugated gold particle is used as probe. The main advantage of these biosensors is not requiring any instruments, multiple incubation and washing steps. Integral part of strip consists of gold particles, with oligo (dT) attached to their surface. Biotinylated PCR products are hybridized with poly (dA) tailed oligo, switched to the top of strip and immersed in the appropriate buffer. With the migration of buffer in upward direction, the nanoparticles that are linked through target DNA through poly (dA/dT) hybridization are rehydrated. Immobilized streptavidin then capture the hybrid in the controlled zone of the strip. The test is 8-10 times more sensitive than ethidium bromide in agarose gel electrophoresis. The detection limit is abysmally low of 2 fmol of amplified DNA products. DNA Biochips Microarrays, DNA arrays, gene chips or biochips are same terminology often being intermixed. DNA microarrays are small, solid supports which themselves are usually microscopic slides, but can also be silicon chips or nylon membranes onto which the sequences from thousands of different genes are immobilized, or attached, at fixed locations. The DNA may be spotted, or synthesized directly onto the support. DNA microarrays detect the change in gene expression levels, genomic gained and losses, mutations in DNA and infectious agents, diagnosis of genetic diseases, drug screening or forensic analysis. Developing the methods for detecting target hybridization, designing probe arrays, data analysis and reconstructing the target sequence are required for successful implementation of DNA chip technology. Such array technology thus forms the basis of integration of molecular biology, surface and analytical chemistry, advanced micro fabrication, robotics, software and automation. In this technique, RNA extracted from two samples are labeled with two different fluorochromes (generally the green cyanine 3 and the red cyanine 5 (Cy3, Cy5)) before being hybridized to a biochip consisting of large numbers of cDNAs/oligonucleotides arranged orderly onto a glass microscopic slide. After hybridization, a scanner records excitation of the two fluorochromes at given wavelengths and the intensity of the fluorescence emission signals that is proportional to transcript levels in the biological samples. The data is analyzed using specific software that enables clustering of genes with similar expression patterns, with the assumption that they share common biological functions [33, 44]. A new ultrasensitive electronic sensor has been developed by Singapore scientists that would speed up effectively DNA testing for disease diagnosis and biological research. The novel electronic sensor array would be faster, accurate and cost-efficient. Excellent sensitivity has been shown by the Nanogap Sensor Array in detecting the trace amounts of DNA. By saving time and cutting expenses, newly developed Nanogap Sensor Array offers a scalable and viable alternative for DNA testing. The presence of DNA is translated into an electrical signal by biosensor for computer analysis. The distinctively and meticulously designed sensor chip has the ability to detect DNA efficiently. The novel vertical nanostructure design and two different surfaces of the sensor allow ultrasensitive detection of DNA [45]. Lab-on-a-chip (LOC) Lab Chip is a device which involves preparation of sample and detection of DNA array. The objective of this technology is to integrate multiple processes, including collection of sample and pretreatment of it with the DNA extraction, hybridization and detection, on single self-contained microchip i.e. on a microfluidic platform. The capability to do all the processes on a single chip merits excellent advantages in terms of cost, speed, efficacy, effectiveness, contamination, sample consumption and automation. Laboratory transportation to the source of sample will be enabled by such miniaturization of analytical instrumentation. The development of these credit-card sized microlaboratories is commonly based on latest micromachining and microfabrication technologies, utilizing processes well known in the manufacture of electronic circuitry [14]. Cell-omic sensors Cell based detection systems can be combined with the microarray probes generating the hybrid arrays of cells within arrays of DNA/protein probs. This allows multiparameters analysis [46]. Applications of DNA Biosensors Biosensors plays a distinguished role in the field of environmental quality, food analysis, study of biomolecules and their interactions, drug development, crime detection, medical diagnosis, quality control, industrial process control, detection system for biological warfare agents, manufacturing of pharmaceuticals and replacement organs. The applications of DNA biosensor can be classified into three broad categories: sequencing, mutation detection and matching detection [47]. Their main use is for diseases diagnosis. Numerous diseases can be diagnosed and variety of infectious agents can be detected using DNA biosensors. 1. Viral diseases By DNA microarrays Either viral detection were being carried by immunological techniques (i.e. use of enzyme-linked immunosorbent assays (ELISAs) for the detection of circulating virus-specific antibodies) or PCR based techniques (i.e. reverse transcriptase (RT) PCR is used to detect the presence of specific viral genes). Both these approaches possess some limitations. Immunological tests need specific antisera and the production of antisera is laborious and time-consuming task whereas PCR is prone to failure in its ability to identify multiple viruses simultaneously [48]. Therefore, recent advances in DNA and protein microarray methodology fulfill the need of a rapid and sensitive detection of viral infections (also identify multiple viruses in parallel). DNA microarrays for viral analysis can be divided into viral chips and host chips. Each not only detects and identifies but also monitor the viral populations. In 1999, the first viral DNA microarray for the temporal profiling of viral (human cytomegalovirus, HCMV) gene expression was described. Viral replication or de novo protein synthesis was blocked by treatment of infected cells with cycloheximide or ganciclovir and then the expression profiles of viral genes was generated using microarray. Using this approach, the HCMV genes were classified to immediate-early, early or late expression classes, on the basis of their expression profile in response to the drug treatments. This can be used as an identifying hybridization signature for the molecular staging of an infection [49]. Orthopoxvirus causes smallpox and has two subtypes variola major and variola minor, of differing pathogenicity. This problem of orthopoxvirus subtype discrimination was solved by producing an array capable of correctly identifying the four of the orthopoxvirus species by laassri etal. [50]. HIV genotyping was done using chip technology [51]. A unique signature that is derived from viral is provided by viral chips. Host chip is used for examining the host response i.e. changes in host gene expression. This provides a molecular signature of infection. Cummings and Relman exposed an idea of host chips [52]. Vant wout etal. examined HIV 1 infection in CD4+ T-cells to detect changes in host gene expression that were specific to HIV infection [53]. Proinflammatory genes and genes involved in endoplasmic reticulum stress pathways, cell cycle, and apoptosis were the host gene signatures identified. Detection of hepatitis B virus Hepatitis B virus (HBV) is one of the causative agents of viral hepatitis which is leading cause of liver cancer. Infection of HBV is a public health menace for worldwide resulting acute and chronic clinical consequences. Acute HBV infection may lead to liver failure or may progress to chronic liver disease. Some chronically infected individuals may subsequently suffer cirrhosis and liver failure or develop hepatocellular carcinoma. Effective antiviral therapy may inhibit or retard the progression to severe liver disease. By DNA optical biosensor Bacterial alkaline phosphatase (phoA) gene and hepatitis B virus (HBV) DNA were used as target DNA. For capturing the target gene onto streptavidin coated magnetic beads, a biotinylated DNA probe was used. A calf intestine alkaline phosphatase labeled DNA probe was used for subsequent enzymatic chemiluminescences detection. The detection cycle was less than 30 min, excluding the DNA hybridization time that was about 100 min. at fematomole or picogramme levels both phoA gene and HBV DNA could be detected. No response signal was obtained when in sample target DNA did not exist [54]. By Piezoelectric DNA biosensor HBV nucleic acid probe was immobilized onto the coated gold surface of quartz crystal using polyethyleneimine adhesion, glutaraldehyde cross-linking (PEI-Glu) method or the physical adsorption method. Better results were obtained with the coated crystal with the PEI Glu method to immobilized HBV nucleic acid probe than physical adsorption method with respect to sensitivity, reproducibility and stability. With the hybridization reaction, the mass is increasing that resulted change in oscillating frequency. The frequency shifts of hybridization have better linear relationship with the amount of HBV DNA, when the amount was in range of 0.02-0.14 microgram/ml [55]. By electrochemical DNA biosensor An electrochemical DNA biosensor that is a glassy carbon electrode (GCE) modified with label free21mer single-stranded (ss) oligonucleotides (related to hepatitis B virus sequence) via covalent immobilization. [Cu(dmp)(H2O)Cl2] (dmp = 2,9-dimethyl-1,10-phenanthroline) is used as an electrochemical indicator. The method is simple, economical and allows the accumulation of copper complex within the DNA layer. Cyclic voltammetry and differential pulse voltammetry were used for electrochemical detection. The detection of hybridization is accomplished by using [Cu(dmp)(H2O)Cl2], where electroactivity and strong association with the immobilized dsDNA segment lead to significantly enhanced voltammetric signal. The differential pulse voltammograms for the cathodic signals of [Cu(dmp)(H2O)Cl2] at a bare GCE, and at ss- and dsDNA-modified GCEs are also recorded. The peak currents of [Cu(dmp)(H2O)Cl2] increased in the order of bare GCE, ssDNA/GCE, and dsDNA/GCE. After hybridization process, a greater peak current was observed from dsDNA/GCE than at ssDNA/GCE, because that more [Cu(dmp)(H2O)Cl2] molecules are concentrated or bound to dsDNA helix than to ssDNA. Thus, [Cu(dmp)(H2O)Cl2] can be used as an electroactive indicator for recognition of the surface hybridization process. The sensitivity of the electrochemical hybridization assay was investigated by varying the target oligonucleotides concentration. The different current value obtained in the DPV response of [Cu(dmp)(H2O)Cl2] after hybridization of probe with target is recorded with three repetitive measurements. The current response at about 0.485V increased in proportion to the amount of the target sequence used [56]. Detection of hepatitis C 3a virus An electrochemical DNA biosensor i.e. a gold electrode modified with a monolayer of a peptide nucleic acid probe and 6-mercapto-1-hexanol was used that depends on covalent binding of the14-mer PNA probe (related to the HCV genotype 3a (pHCV3a) core/E1 region) onto the electrode. This self-assembled PNA could selectively hybridize with a complementary sequence in solution to give dsPNA-DNA on the surface, and this increases the peak current of methylene blue (MB) which is used for detecting target DNA sequence. Diagnostic performance of the biosensor is described and the detection limit was found to be 5.7  ÃƒÆ'-  10à ¢Ã‹â€ Ã¢â‚¬â„¢11  M with a relative standard deviation of 1.4% in phosphate buffer solution, pH 7.0. This sensor exhibits high reproducibility and could be used to detect the target DNA for seven times after the regeneration process [57]. Cystic fibrosis Mikkelsens team, pioneered the utilization of redox indicators, demonstrated utility of electrochemical DNA biosensor for detecting the cystic fibrosis F508 deletion sequence which is associated with 70% of cystic fibrosis patients. For the 4000-base DNA fragment, 1.8 fmol was the detection limit in relation to a Co(bpy)33+ indicator. High selectivity for the disease sequence (not for normal DNA) was accomplished by doing the hybridization at high (43 °C) temperature [14]. 3. Diabetes Diabetes is a worldwide public health problem. The diagnosis and management of diabetes requires a tight monitoring of blood glucose levels. Thus millions of diabetics test their blood glucose levels daily by making glucose the most commonly tested analyte. The challenge is to provide such reliable and tight glycemic control. Electrochemical biosensors for glucose thus play a leading role. Amperometric enzyme electrodes, based on glucose oxidase (GOx) bound to electrode transducers, have thus been found the subject of substantial research [58]. Glucose sensors are commonly used to measure the blood glucose level of diabetes patients. Using the latest DNA chip technology, many scientists at Diabetes Center have discovered the implication of new gene in the cause of type 2 diabetes. They created an abnormality in one of these genes known as ARNT (aryl hydrocarbon receptor nuclear translocator gene which is a member of a family of transcription factors) in mice and the mice developed changes in insulin secretion which were same as in patients with type 2 diabetes. The ARNT is required for the development of normal embryo. It is also related to responses to hypoxic stress condition and certain environmental toxins, such as dioxin and thus for integrating genetic and environmental insults it is present at specific potential sites. The expression of many other genes in the cell is regulated by transcription factors like ARNT and thus they are the master regulators of cellular functions. The first use of DNA chips has been represented by this study,

The Web of Knowledge Essay -- Philosophy Papers

The Web of Knowledge Great theorist and philosophers such as the stoics, skeptics, Aristotle, St. Thomas Aquinas, Descartes, Spinoza, Locke, Hume, Berkeley, Kant, Bertrand Russell, Darwin, Freud, and all of 20th century science have struggled with the question what is knowledge? and can we have knowledge? "To know" and "knowledge" are potent concepts and before taking Text and Critics, I took it for granted that I had knowledge of what knowledge is. Then came a simple question. After reading The American Scholar, I recall the class being asked "how is nature related to knowledge?" I didn't have an answer. But more importantly, before I could answer the former, I realized I didn't "know" what knowledge is. How could it be that I had never considered one of the most important philosophical questions asked of mankind--what can we know and what is knowledge? There have been many different views about knowledge, but none of the major philosophers, perhaps because knowledge is such a potent concept and its understanding is assumed to be self evident, have explained what knowledge is. For example, I have here some views with knowledge but no definition of knowledge: Chuang-Tzu, the old Chinese sage and poet said: "Once I dreamed I was a butterfly, and now I no longer know whether I am Chuang-Tzu, who dreamed I was a butterfly, or whether I am a butterfly dreaming that I am Chuang-Tzu." Black Elk, the Lakota moralist, told John Neihardt: "That is the real world that is behind this one, and everything we see or hear is something like a shadow from that world." So, too, was it for Plato. Ralph Waldo Emerson wrote in The American Scholar : "We all know, that as the human body can be nourished on any food, though it were boiled grass ... ...rowning in information and starved for knowledge --Unknown "By necessity, by proclivity, and by delight we all quote. In fact it is as difficult to appropriate the thoughts of others as it is to invent." --Ralph Waldo Emerson References Neihardt, John. 1961. Black Elk Speaks . Lincoln and London, Nebraska: University of Nebraska Press. Confucius. 1989. The Analects of Confucius. New York: Vintage Books, A division of Random House, Inc. Gaarder, Jostein. 1996. Sophie's World, A Novel About the History of Philosophy. New York: Berkeley Books. Emerson, Ralph Waldo. The American Scholar. Aristotle. The Nicomachean Ethics. Custom Course Packet. Plato.1984. The Great Dialogues of Plato. New York, New York: Mentor. Quotes not from text T&C text, above, or otherwise mentioned are from: http://www. starlingtech.com/quotes/qsearch.cgi The Web of Knowledge Essay -- Philosophy Papers The Web of Knowledge Great theorist and philosophers such as the stoics, skeptics, Aristotle, St. Thomas Aquinas, Descartes, Spinoza, Locke, Hume, Berkeley, Kant, Bertrand Russell, Darwin, Freud, and all of 20th century science have struggled with the question what is knowledge? and can we have knowledge? "To know" and "knowledge" are potent concepts and before taking Text and Critics, I took it for granted that I had knowledge of what knowledge is. Then came a simple question. After reading The American Scholar, I recall the class being asked "how is nature related to knowledge?" I didn't have an answer. But more importantly, before I could answer the former, I realized I didn't "know" what knowledge is. How could it be that I had never considered one of the most important philosophical questions asked of mankind--what can we know and what is knowledge? There have been many different views about knowledge, but none of the major philosophers, perhaps because knowledge is such a potent concept and its understanding is assumed to be self evident, have explained what knowledge is. For example, I have here some views with knowledge but no definition of knowledge: Chuang-Tzu, the old Chinese sage and poet said: "Once I dreamed I was a butterfly, and now I no longer know whether I am Chuang-Tzu, who dreamed I was a butterfly, or whether I am a butterfly dreaming that I am Chuang-Tzu." Black Elk, the Lakota moralist, told John Neihardt: "That is the real world that is behind this one, and everything we see or hear is something like a shadow from that world." So, too, was it for Plato. Ralph Waldo Emerson wrote in The American Scholar : "We all know, that as the human body can be nourished on any food, though it were boiled grass ... ...rowning in information and starved for knowledge --Unknown "By necessity, by proclivity, and by delight we all quote. In fact it is as difficult to appropriate the thoughts of others as it is to invent." --Ralph Waldo Emerson References Neihardt, John. 1961. Black Elk Speaks . Lincoln and London, Nebraska: University of Nebraska Press. Confucius. 1989. The Analects of Confucius. New York: Vintage Books, A division of Random House, Inc. Gaarder, Jostein. 1996. Sophie's World, A Novel About the History of Philosophy. New York: Berkeley Books. Emerson, Ralph Waldo. The American Scholar. Aristotle. The Nicomachean Ethics. Custom Course Packet. Plato.1984. The Great Dialogues of Plato. New York, New York: Mentor. Quotes not from text T&C text, above, or otherwise mentioned are from: http://www. starlingtech.com/quotes/qsearch.cgi