tag:blogger.com,1999:blog-3949761534200395390.post8620059771223324302..comments2024-01-03T17:27:11.545+01:00Comments on The Space of Reasons: Outline of Nozick's "Knowledge"AVERY ARCHERhttp://www.blogger.com/profile/14313322464414110953noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-3949761534200395390.post-27191974677491861952016-04-19T10:46:00.845+01:002016-04-19T10:46:00.845+01:00Thanks for stopping by and for the kind words, Eth...Thanks for stopping by and for the kind words, Ethan. I have fond memories of the UT logic classes. Hope you're well.AVERY ARCHERhttps://www.blogger.com/profile/14313322464414110953noreply@blogger.comtag:blogger.com,1999:blog-3949761534200395390.post-35505878116884838102016-04-18T22:02:14.079+01:002016-04-18T22:02:14.079+01:00Hello Dr. Archer. I came across your blog doing so...Hello Dr. Archer. I came across your blog doing some research for E.J. Coffman's epistemology class at UT and I recognized your name from having you as my formal logic teacher. I wanted to say that this is a great blog post, that your logic class was one of my favorite classes, and that I hope you're doing well in D.C.Ethan Linehanhttps://www.facebook.com/ethan.linehannoreply@blogger.comtag:blogger.com,1999:blog-3949761534200395390.post-72951679214682640002012-04-30T21:02:34.521+01:002012-04-30T21:02:34.521+01:00I think it's clear that, as presented, Nozick ...I think it's clear that, as presented, Nozick seems to have the best case. That said, I'm not convinced that he's right or that other accounts can't be repaired well enough to eventually surpass it. Even ignoring the Jesse James example, I'm pretty unhappy with the lack of clarity thus far on `nearest possible worlds' and unconvinced that knowledge shouldn't be closed under entailment. The latter, especially, seems highly counterintuitive to me.<br /><br />In response to the conversation on skepticism thus far, I'm going to have to disagree with Benjamin's suggestion that the envater's electrical stimulation is powerful enough to change propositional logic. If by `propositional logic' we mean the formal logical system, it is entirely definitional, and I struggle to see how it can be changed and yet remain propositional logic. Say, for example, that the envaters decide to make a minor change to the truth-functionality of 'v'--in this case, no longer is propositional logic under consideration, but rather an entirely different system that bares some resemblance to propositional logic. I take Benjamin's point to be, then, that the envaters have the ability not to change propositional logic, but rather to convince the envated brain that a different system tracks truth when it, in fact, does not (i.e. that another system occupies the space most believe to be occupied by propositional logic). To do so requires not just that the envaters produce a new reality, but that they actively control what the brain believes is possible based on meaning; in particular, they must make some things impossible or unconceivable which are possible/conceivable to preserve their system, and some things possible/conceivable which are impossible/unconceivable in order to rule out propositional logic proper. These actions are categorically stronger than simply affecting a brain's sense perceptions and less obviously possible. Indeed, I believe you need to make quite a few non-controversial assumptions about the mind to do so.<br /><br />Moving to Benjamin's main argument, I agree completely with Taylor; the argument fails because--even if we grant the envater's the ability to control our notion of possibility / conceivability--there's absolutely no reason why they couldn't stimulate the belief that we might be a brain in a vat. Thus having this belief in no way undermines that possibility.<br /><br />Finally, I think Andrew's argument is an interesting one (although I disagree with it as well). To make it work, though, we need to both explicate how the world against which something is being evaluated is selected and to accept that there are (apparently) infinitely many such possible worlds. Of course, there's also the problem that I certainly don't think I'm just talking past someone when I say they don't know the world exists (and they assert they do) and that competing accounts will have an Occam's razor argument against his proposal (in particular, I think a subsistent entities account could deal a great deal of damage).Russell Buehlernoreply@blogger.comtag:blogger.com,1999:blog-3949761534200395390.post-90931841221371869132012-04-24T07:01:57.424+00:002012-04-24T07:01:57.424+00:00I agree with both of the above posts in terms of q...I agree with both of the above posts in terms of question 3, in that through logic, we cannot know for certain that we are not "brains in vats" as suggested by the skeptics, but rather we must set a foundation for our knowledge in the known world, similar to our earlier unicorn examples. <br /><br />For instance, when the two propositions "Charlie is a unicorn" and "unicorns do not exist" are put forth, both are considered true, but based on different understandings. The first is true in the fictional world created by the artist of Charlie, since unicorns cannot exist in our "real" world. Whereas the first has a foundation in a fictional world, the second has a foundation in out "real" world, and is thus true for those parameters. Thus, when determining knowledge, it is important to realize the parameters with which one works. In this case, we have knowledge of our world as we perceive it to be true. There are laws of nature, tendencies which have been repeated and proven to be true, and this is what we consider to be true in this case. As such, we have knowledge of this supposed "real" world. Simply because we might be brains in vats has no bearing on the fact that we know and understand how the world which we perceive works and operates on a daily basis. Just as we have knowledge of the fictional world of charlie the unicorn as a subset of our "real" world, we would also be able to have knowledge concerning our perceived "real" world as a subset of our possible brain in vats world.Andrew Celynoreply@blogger.comtag:blogger.com,1999:blog-3949761534200395390.post-75261415379027250482012-04-24T02:43:28.570+00:002012-04-24T02:43:28.570+00:00First of all, I have to say I'm a pretty big N...First of all, I have to say I'm a pretty big Nozick fan at this point, Jesse James example notwithstanding. I see that there's some tightening up to do on the closest possible world side of things, but this also seems like an area where we already have some intuitions to guide us toward the beginnings of a definition. For example, in the Jesse James example we talked about, my instinct is that changing the moment when the mask falls off is in some way not in the spirit of the question we are actually asking. I'm not sure that restricting things to the same mode of perception like we talked about in class completely solves the problem, but it is a start.<br /><br />In response to question 3, we have to clarify that Nozick agrees with the skeptic that we cannot know we are not brains in vats. However, we can know that we are, in my case, sitting in a chair in the libe. The skeptic's case that we do not know this relies on the logical implication that because I do not know p (that I'm not a brain in a vat) that I don't know q, which is logically implied by p (that I'm in the libe). Nozick argues that this isn't so, because my belief that q must vary with q's truth, which it doesn't if I only use logic to conclude q. Therefore my uncertainty about whether I'm a brain in a vat doesn't transfer to uncertainty about whether I'm sitting in the libe. If I understood this all correctly, that is. <br />In response to Ben, I'm not sure that imagining a possible world in which we are brains in vats that additionally can't be skeptical gets us anywhere new, as there is an equally possible world in which we are brains in vats that are only being given incorrect sensory stimuli about where we are, in which case skepticism and being in a vat are not mutually exclusive.Taylor ffitchnoreply@blogger.comtag:blogger.com,1999:blog-3949761534200395390.post-16848637584006964132012-04-22T22:13:56.059+00:002012-04-22T22:13:56.059+00:00Nozick faces the nameless skeptic, but seems to fa...Nozick faces the nameless skeptic, but seems to fare victoriously despite conceding some points to his opponent. Nozick grants that his theory of knowledge cannot deny the possibility of skeptical arguments (SK). However lack of evidence against something does not make it true. While we don't track the fact that SK doesn't hold, we do track some other facts, some of which challenge SK. As long as the skeptic also buys into these basic truths that we track and hold to be true, it is difficult to maintain support for a skeptical argument. Thus, Nozick ventures that the skeptic is mistaken. <br /><br />This makes sense to me and goes to show how hard it is out there for a skeptic, but I wonder if we cannot take this one step further:<br />Even if we were brains in vats, we would not believe we were brains in vats, and further would not know that we were brains in vats. This is because, as the SK goes, the alleged brains in vats receive electrical stimulation to believe they are not brains in vats. If this electrical stimulation is powerful enough to construct a reality separate from in-vat existence, surely it is powerful enough to influence propositional logic. More clearly, if we were brains in vats, we would not receive the signals to wonder if we were brains in vats, skeptical of the reality we knew. The ability to be skeptical, I believe, disproves the potential skeptical argument. <br /><br />(That is unless the powers controlling my brain vat want me to write this...)Benjamin Altshulernoreply@blogger.com