Is Knowledge Closed Under Known Entailment - Essay Example

Is knowledge closed under known entailment? Postulation of Forms It is d in the epistemic closure principles that the epistemic set members, for example, the propositions known to me have some sort of relation such as known deductive entailment that are similar to other members in the epistemic set. Under known logical entailment, the closure of knowledge principle states that what they know entails everything that someone knows logically. For example, if I know the sun is yellow or the grass is green, then I am aware that sun is yellow and grass is green. The epistemic closure principles in philosophy are used in countless ways. However, some of the principles have been rejected by theorists thus, remain controversial. This paper seeks to address the question: Is knowledge closed under known entailment. Closure principles are viewed by some people as based on the notion of the possibility increasing earlier level of knowledge through acknowledging the propositions needed by what people are already aware of. Others see this as a misunderstanding in the sense that the principles of closure are silent to what knowledge is or how it could be gained. Based on the principle that under known entailment knowledge is closed, if I am aware of the issue earlier, then I know the contents, making me automatically become aware of the last claim. However, some still insist that this must be differentiated from the false claim possibility that, if I already know the prior, I would know the latter since my basis for being aware of the former entails presupposing the latter by referring to memory and sense experience1. Both anti-skeptical and skeptical arguments use the closure principles. In the skeptical view, people use a known common sense such as the belief that one knows they have hands. This entails the skeptic hypothesis of falsity approach that suggests that, such thoughts are false. The truth is that a person is a handless brain in a vat making all his experiences hallucinations. The falsity entailed within the skeptical hypotheses would be known in virtue of the fact that under the knowledge entailment is being closed. Since the skeptical hypothesis of falsity cannot be known as the skeptics support, the common sense truth must also not be known, which suggests that a person has hands. The anti-skeptics alternatively centralize around the possibility of the failure of people to be aware of the common sense truth proposition, and therefore, in the closure principle virtue, people can become aware of the entailed falsity within the approach of the skeptics. Although anti-skeptics sometimes use the closure principle, some view the closure rejection as the key to the skeptic’s refutation2. The following case argument based on Fred Dretske work will help give a supposed closure counter example. At the zoo, Joe goes to a cage marked zebra. He looks at the caged stripped animal and believes it is a zebra. It seems, in fact, that Joe knows they are zebras. For the animal to be a zebra, then it cannot be a mule that has been cleverly disguised. Joe knowing what a zebra is, he is aware of this fact as well, which leaves the question, if he knows that the animal right in front of him is not a mule, would that have been cleverly disguised? Dretske says, it does not and suggests that this answer is intuitive. Dretske, in support of this claim, states that all of Joe’s evidence that support the animal being a zebra does not count in favor of the animal and as such has been neutralized, since he would hold similar perpetual evidence in this case. This is case in that (1) Joe knows that there are zebras before him and (2) he does not know if these are not cleverly disguised mules (3) even though he would be aware that if an animal is a zebra, then it is not a mule that has been cleverly disguised. Then this counterexample to the principle of closure would hold mainly through argument (1) through (3). However, in the above example (1) through (3) do not hold. This is not a closure counter example. Using Nozick’s ‘truth-tracking’ analysis, several objections can be brought to Dretske’s account. Starting with Joe’s proposed evidence that a zebra is before him, it is also factual that a cleverly disguised mule is not before him. Joe’s evidence for the former, as assumed by Dretske analysis, is entirely his perceptual experience, which is a mistake. Without further background evidence regarding the nature of zookeepers, zoos and the difficulty in so disguising a mule, Joe will then not be justified in believing that there is a zebra before him. Without such assumed background evidence like the ones in the case, it is false that Joe is justified in believing that there is a zebra standing in front of him. By imagining a case where Joe and the zebra have the same perceptual experience, this can be seen, but it is in a context completely unrelated or unfamiliar to him. In such cases, it is far from clear whether Joe knows if there is a zebra before him3. However, when attached with the proper background evidence, Joe’s perceptual evidence is also a fact that points out that there is no painted mule before him. Concerning considerations about the nature of zookeepers, zoos and the difficulty in disguising a mule, make the sole belief that a zebra is before him; the only epistemic belief Joe ought to entertain. What more is needed for knowledge? Joe’s belief is true, justified and not subject to any Gettier considerations. Thus, if for Joe this evidence is good enough to know that there is a mule before him, it is also good enough to be aware that there is no mule that is cleverly disguised before him therefore, preserving the closure4. Dretske might say that even though a child might not have this background evidence, they may yet still be aware that the animal before them is a zebra. one would not be justified in believing if one lacked this background evidence, (and thus would not know) that the animals were not cleverly disguised mules. However, the person in such a case would also not know that there were zebras before her. In such an epistemic situation, it is by no means clear that a child actually knows that there is a zebra before her. Even if the child can differentiate between the fake zebra and the real zebra without the relevant background evidence, she has insufficient reason to prove that the animal is a zebra. In addition, even if it is approved that the child is aware that the animal in question is a zebra, it is unlikely that she can draw the conclusion on cleverly disguised mules, and if she cannot, then the case does not have any closure principle. The insights that Dretske is supporting do not support denial of closure. Typically, people often state that they are sure they saw zebras at the zoo. However, when challenged about what they actually saw, these people may defend their first perceptions on what they envisioned. When this disapproval is made, the first self-knowledge attribution often gets withdrawn at least shortly. The closure response dictates this response. It seems that people never claim to be aware of a proposal and concurrently deny one of that same propositions knowledge known entailment. As such, intuitions are not against it, but support closure. Thus, the knowledge closure principle cannot say that it has been presented with a valid counterexample. To avoid skepticism, Dretske supports the closure rejection. This principle of epistemic asserts that under known entailment knowledge is closed. Therefore, if P is known by S and S is aware that P involves Q, from this aspect, S becomes aware of Q and is acquainted to S. In regards to knowledge, Dretske asserts that there are only two available choices. One is that we accept skepticism and keep closure on knowledge that we ordinarily take for granted like in the case of the hands, and we maintain ordinary knowledge and deny closure (Dretske, 23). John Hawthorne offers a different perspective from that of Dretske. He proposes favoring closure since he advocates that the refusal of closure would cause more damage than what is already there5. To understand why Dretske considers it relevant to demand skepticism in closure, the following have to be considered. In distance (P), Sarah is aware that a farmer is standing since she sees one. In point (a), Sarah is aware that the very idea that a farmer is in the field might not be the case but an animatronics, lifelike scarecrow instead, which translates to (Q). Therefore, in point (b), according to closure, Sarah can know Q based on her knowledge and that Q is entailed in P. this means that the farmer may not be one but just a scarecrow. However, can Sarah really know that what she saw was a scarecrow or not? Has she taken her time to walk and observe what she saw at the field to really be the farmer that is to be sure she was not deceived? If she were not sure about what she is seeing, the idea that it is not the farmer in the field would persist, P à Q, ~ Q, thus ~ P. It seems, indeed, that ordinary knowledge possession seems to suggest that one’s knowledge does not lie, which can be referred to as proto-knowledge according to Dretske. It seems unlikely unintuitive for Sarah to claim being knowledgeable about Q without any evidence, therefore leaving skepticism to continue. Thus, one cannot claim to have knowledge of something when he or she is not sure or does not have evidence to prove that. One may question why Sarah has evidence of P and not Q. In this respect, reviewing evidence that has the information making up knowledge of P means that Sarah views the farmer at the field as bent or waving his hands. However, due to her experience in the past with similar perceptions, she creates the belief that she seeing a farmer in the fields. Yet the evidence of P, according to Sarah, is not in any way transmittable to Q. She cannot deduce that a robotic scarecrow is cheating her by simply observing the farm fields. It would require further knowledge to verify such information. This issue is further enhanced with the “heavyweight implications” proposed by Dretske that through appealing to perception are impossible to determine. Dretske, thus, argues that the closure principles eliminates any knowledge ordinarily, since I am not knowledgeable that I am a brain that is being cheated simultaneously while in a vat state through a mad scientists mechanization, I cannot in any way be aware that currently am seated at home or at work6. Drestske’s heavyweight implications are considered as a disadvantage to ordinary knowledge; in that, if closure offers an alternative between (a) ordinary knowledge without it and (b) skepticism with closure. Dretske chooses the latter. Therefore, Sarah can certain hallucinating and in addition she actually saw the farmer at the fields while not be sure that the scarecrow was at the fields. Hawthorne’s arguments against Dretske’s proposal do not provide a formidable solution to the closure problem, but it leads to greater issues than the ones it claims to solve. The refusal of the intuitive closure principle is one such problem that leads to the rejection of even more distribution intuitive principles also (Hawthorne, 31-32). Closure on the other hand is based upon entailment logically, and upon logical equivalence, the distribution is based. The propositions that a farmer is in the field thus, is similar to the notion that it is not the farmer but the animated scarecrow that is based in the field. Sarah, according to distribution can be in a better place to know that it is not the farmer that is in the field in this case but an animated scarecrow instead. It is incredibly difficult to know the conjunction of Q and P but not that of Hawthorne, indeed demonstrates that the closure rejection is not nearly as pleasant as Dretske claims7. As mentioned earlier, Hawthorne does not solve the inherent issues in maintaining closure. He even goes a step further to offer his own implied closure quandary in his example (39) in the Misprint. It turns out that the results were opposite and this entails that it was a misprint. It seems incredible odd however to say that I am sure there was no misprint since I am sure the panthers were victorious from reading the papers. This is similar to telling a skeptic that is they should just ask you if they do not believe you. Contextualizim is offered by Hawthorne as a possible answer to the closure issues. However, he admits readily that the problem in this perspective is that philosophers understanding of skeptics give them the right to be ranked among the least intelligent people internationally. Hawthorne believes that this option argues that doing so would be more damaging than solving, while Dretske believes that the closure denial is the most plausible8. In conclusion, both sides of the Dretke’s and Hawthorne’s dilemmas are nasty, and I believe that both philosophers offer a solution that is compelling to the closure problem. However, it is easier to embrace skepticism as compared to refusing the closure principles mainly since refuting the closure principles seems equivalent to refusing logical similarities as well. The logic in this Hawthorne’s argument standout from the rest. The denial of closure, however, seems to be very close to a refusal of denial logic and one cannot understand how it is possible to know P as P yet not know ~ P. Similar to Hawthorne and Dretske, I have no compelling solution to the issue that knowledge closure presents. However, Hawthorne’s side provides much insight into the problem of whether knowledge is closed under known entailment. Reference List Alston, W., The Reliability of Sense Perception, Ithaca: Cornell University Press. (1993), 65-76 Brueckner, Anthony, “Strategies for Refuting Closure,” Analysis, 64(2004): 333-35. Bogdan, R.J., “Cognition and Epistemic Closure,” American Philosophical Quarterly, (1985)22: 55–63. DeRose, K., “Solving the Skeptical Problem,” Philosophical Review, (1995)104: 1–52. Dretske, Fred. “The Case against Closure,” in Steup and Sosa (eds.), (2005), 13-26. Hawthorne, John “The Case for Closure,” in Steup and Sosa (eds.), (2005), 26-43. Nozick, R. Philosophical Explanations. Cambridge MA: Harvard University Press, (1981) pp172-85, 197-217 Putnam, Hilary, “The Meaning of ‘Meaning’,” in K. Gunderson (ed.), (1975), 131-193. Thalberg, Irving, “Is Justification Transmissible Through Deduction?” Philosophical Studies 25(1974): 347-356. Stine, Gail “Dretske on Knowing the Logical Consequences,” Journal of Philosophy 68(1970): 296-299. Read More