Dretske on Knowledge Closure

In early essays and in more recent work, Fred Dretske argues against the closure of perception, perceptual knowledge, and knowledge itself. In this essay I review his case and suggest that, in a useful sense, perception is closed, and that, while perceptual knowledge is not closed under entailment, perceptually based knowledge is closed, and so is knowledge itself. On my approach, which emphasizes the safe indication account of knowledge, we can both perceive, and know, that sceptical scenarios (such as being a brain in a vat) do not hold

The Easy Argument

Suppose Ted is in an ordinary house in good viewing conditions and believes red, his table is red, entirely because he sees his table and its color; he also believes not-white, it is false that his table is white and illuminated by a red light, because not-white is entailed by red. The following three claims about this table case clash, but each seems plausible: 1. Ted’s epistemic position is strong enough for him to know red. 2. Ted cannot know not-white on the basis of red. 3. The epistemic closure principle, suitably restricted, is true. Stewart Cohen has called this three-way clash of intuitions the problem of easy knowledge. If we wish to resolve the clash without accepting skepticism, we seem to have two options. According to the hard argument, the best response is to reject 3. The easy argument rejects 2. But there may be a third alternative, the reverse argument, which rejects 1 without ceding a substantial amount of ground to the skeptic. In this essay I criticize recent versions of the reverse argument and the hard argument, thereby lending support to the easy argument

The Moral Standing of the Dead

In choosing to do certain things, we appear to presuppose that we can act in the interests the dead, and that we have a duty to do so. For example, some of us go to great lengths to carry out their final wishes. Given that the dead no longer exist, however, it seems that nothing can be good or bad for them: they lack prudential interests. In that case, it is hard to see how we could owe them anything. They seem to lack moral standing altogether. In this essay, I will rebut this line of thought. I will claim that in some cases things that happen after people die are indeed good or bad for them. Their interests can still be advanced or hindered, so the dead have moral standing

Past Desires and The Dead

I examine an argument that appears to take us from Parfit’s [Reasons and Persons, Oxford: Clarendon Press (1984)] thesis that we have no reason to fulfill desires we no longer care about to the conclusion that the effect of posthumous events on our desires is a matter of indifference (the post-mortem thesis). I suspect that many of Parfit’s readers, including Vorobej [Philosophical Studies 90 (1998) 305], think that he is committed to (something like) this reasoning, and that Parfit must therefore give up the post-mortem thesis. However, as it turns out, the argument is subtly equivocal and does not commit Parfit to the post-mortem thesis. I close with some doubts about Parfit’s case for his indifference thesis

Mortal Harm

The harm thesis says that death may harm the individual who dies. The posthumous harm thesis says that posthumous events may harm those who die. Epicurus rejects both theses, claiming that there is no subject who is harmed, no clear harm which is received, and no clear time when any harm is received. Feldman rescues the harm thesis with solutions to Epicurus\u27 three puzzles based on his own version of the deprivation account of harm. But many critics, among them Lamont, Grey, Feit and Bradley, have rejected Feldman\u27s solution to the timing puzzle, offering their own solutions in its place. I discuss these solutions to the timing puzzle, and defend the view that while we are alive we may incur harm for which death and posthumous events are responsible

False Negatives

In Philosophical Explanations, Robert Nozick suggested that knowing that some proposition, p, is true is a matter of being “sensitive” to p’s truth-value. It requires that one’s belief state concerning p vary appropriately with the truth-value of p as the latter shifts in relevant possible worlds. Nozick fleshed out this sketchy view with a specific analysis of what sensitivity entails. Famously, he drew upon this analysis in order to explain how common-sense knowledge claims, such as my claim to know I have hands, are true, even though we do not know that skeptical hypotheses are false. His explanation hinged on rejecting the principle that knowledge is closed under (known) entailment. In this chapter I will criticize Nozick’s view of knowledge as “sensitivity” to truth-value. In doing so, I mean to undermine his case against the closure principle and against the claim that we do not know that skeptical hypotheses are false. I begin with a review of Nozick’s notion of sensitivity and his analysis thereof

Adaptation

Some ways of dealing with a threatened evil will be self-defeating, in the sense that the response is no better for us, or even worse, than the evil it prevents. A way of adapting to death might be self-defeating in precisely the same way. Perhaps, however, we can adapt to death by suitably modifying our interests, and do so in a way that is not self-defeating. I will call this claim the adaptation thesis. Elsewhere, I have argued against it. In this chapter, I reinforce that conclusion

Posthumous Harm

According to Epicurus (1966a,b), neither death, nor anything that occurs later, can harm those who die, because people who die are not made to suffer as a result of either. In response, many philosophers (e.g., Nagel 1970, Feinberg 1984, and Pitcher 1984) have argued that Epicurus is wrong on both counts. They have defended the mortem thesis: death may harm those who die. They have also defended the post-mortem thesis: posthumous events may harm people who die. Their arguments for this joint view are by now quite familiar, and there is no need to rehearse them here (for a summary, see Luper 2002). Instead, our topic is a third position, which carves out intermediate ground between the other two. The intermediate view takes the mortem thesis for granted, like the critics of Epicurus, but rejects the post-mortem thesis, like Epicurus himself. For Epicurus’ project—the attainment of ataraxia, or equanimity—the intermediate view is almost useless (we are not tranquil if we regard death as a tragedy whose peculiarity is that it frees us from the possibility of any further misfortune); however, it is far more plausible than Epicurus’ own position since it avoids his absurd claim that death cannot harm us, while retaining his view that events occurring while we are dead and gone cannot harm us. According to the proponent of the intermediate view, when we understand the harm death inflicts, we must reject the idea that events following death can be bad for us. The damage death itself does is so severe that people are not subject to harm by any subsequent events. Thus the intermediate view rests on the mortem thesis 2 together with the immunity thesis: death leaves its victims immune from posthumous harm. The immunity thesis is quite plausible. Truly, once death is through with us, very little can be bad for us. However, this essay will show that the immunity thesis faces significant objections. Hence even though the mortem thesis is correct, the intermediate thesis is questionable. The point is important, because of the consequences of the view that posthumous events are harmless to us. One such consequence is that it is irrational to care how our reputations or personal projects will fare after we die. It also follows that keeping our bodies alive after our brains enter a persistent vegetative state is not beneficial to us. Moreover, there is a strong prima facie case for the view that others should feel free to set aside any instructions we might leave behind concerning the disposition of our material possessions

The Knower, Inside and Out

Adherents of the epistemological position called internalism typically believe that the view they oppose, called externalism, is such a new and radical departure from the established way of seeing knowledge that its implications are uninteresting. Perhaps it is relatively novel, but the approach to knowledge with the greatest antiquity is the one that equates it with certainty, and while this conception is amenable to the demands of the internalist, it is also a non-starter in the opinion of almost all contemporary epistemologists since obviously it directly implies that we know nothing about the world. Perhaps skepticism is correct, but there are conceptions of knowledge at least as plausible as the certainty equation that do not obviously land us there. It is its promise along these lines that makes the so-called ‘traditional’ conception of knowledge initially interesting. But contrary to popular belief, the traditional conception cannot be claimed by internalists if it is to have any chance at all in avoiding skepticism; to avoid skepticism, I shall argue, it has to have an externalist element. Moreover, each of the departures from the traditional view that appears in the Gettier literature is externalist as well, or at least all of the ones of which I am aware. The only genuine forms of internalism are those held by philosophers who draw a fairly sharp line between knowledge and justified belief, ignore the former, then offer an internalist account of the latter. This approach is very common and very plausible. But it is not as useful as is often thought; in particular, I shall suggest, it must succumb to a form of skepticism

Indiscernability Skepticism

Ideally, our account of knowledge would help us to understand the appeal of (and flaws in) skepticism,2 while remaining consistent with our ‘intuitions,’ and supporting epistemic principles that seem eminently plausible. Of course, we don’t always get what we want; we may not be able to move from intuitions and principles to an account that fully squares with them. As a last resort, we may have to move in the other direction, and give up intuitions or principles that are undermined by an otherwise compelling account of knowledge, so as to achieve ‘reflective equilibrium.’3 But last resorts come last