JCCMI- Week 6 Discussion 1 and 2

Week 6 – Lecture 2: An Argument Against Skepticism, John Hospers

Skepticism is best characterized as a disposition or attitude of doubt; in philosophy, the doubt is typically doubt of whether some knowledge or any knowledge is available. If Ereni is skeptical about Extra Sensory Perception (ESP), Ereni doubts that humans have the capacity for ESP. If Brenda is skeptical of Bob’s claim that he’s an expert spelunker, Brenda has doubts about Bob’s claim. We saw that Descartes tried to be skeptical of everything. We might call this “global skepticism”, where the adjective “global” indicates that the doubt concerns all things. In this reading, John Hospers argues against this sort of skepticism. His challenge is to show that some things can be known. As you read along, try to see if Hospers at any point assumes something that Descartes would doubt. If he does, then Descartes would reject his argument. That is, if Hospers doesn’t argue that some knowledge is possible but just assumes it, then his argument against skepticism fails.

Hospers characterizes knowledge in the same way Plato did: a person, S, knows a proposition P when three conditions are met: (1) P is true; (2) S believes that P; and, (3) S has evidence that P is true. Hospers sets this up nicely, I think, but if you have questions about any of these conditions, please raise them on the course site or email me. Many people balk when they first hear that S doesn’t know that P if P isn’t true. Feel encouraged to ask questions about this.

Once he has said that knowledge requires evidence, Hospers points out that we should like to have more precision in this criterion: how much evidence do we require? Is just some evidence enough? Do we need all the evidence? As Hospers makes pretty clear, the problem is a dilemma. A dilemma is a situation in which we face two options and both options are bad. Here, our two options are choices about how much evidence we might say is required for knowledge. On the one hand, we might say that S knows P only if S has enough evidence to guarantee that P is true. In this case, you know that the world won’t end before next Tuesday only if you can absolutely guarantee it—only if your evidence that the world won’t end before next Tuesday logically entails that it won’t. If your evidence is logically consistent with the world’s ending in less than a week, then you don’t know that it won’t in fact end. This is the first option in the dilemma. What makes it bad, of course, is that if it’s true, then we know next to nothing (or maybe we know nothing). If your evidence doesn’t guarantee it, you don’t know it.

The other choice in the dilemma is to say that S’s evidence for P doesn’t need to guarantee P’s truth. You can know that the world won’t end before next Tuesday even if your evidence for it is logically consistent with the world really ending before next Tuesday. This choice will make it so that we do know a number of things, but it will let us down in a number of cases. Indeed, the problem here is exactly that the evidence won’t guarantee truth. If knowledge is like this, then you might have enough evidence to say today that you know it won’t rain tomorrow. But then suppose it rains tomorrow. Then the thing you said you knew wasn’t true. So you didn’t know it. Hospers thinks this is a problem.

He proposes to solve this problem by distinguishing between two senses of “know”, a strong and a weak sense. On both senses, the above three conditions are met, but they differ with respect to the third condition; that is, they differ in how much evidence they require. On the strong sense, to say that “S knows that P” is to say that S’s evidence guarantees that P is true. This is the sense that Descartes uses. On the weak sense, to say that “S knows that P” is to say that S’s evidence gives her good reason to believe P. This is the sense that we usually use when we’re not doing philosophy or science or math. With this distinction in hand, Hospers argues for using the weak sense and against using the strong sense.

First, Hospers argues in favor of the weak sense that just because one’s evidence for P didn’t guarantee P, this doesn’t show that there was something wrong with the evidence. Recall the case above in which you said you knew it would rain tomorrow but then it didn’t rain. Although we might say on Sunday that you know it won’t rain Monday, when Monday comes and it rains, we should say we were wrong—as it turns out, you didn’t know on Sunday that it would rain Monday. We want to take back the knowledge we attributed to you. It’s tempting to say that you didn’t know because your evidence was inadequate, but we don’t have to say this. Rather, we can explain why you didn’t know in another way: the P you claimed to know was false. That is, it didn’t rain Monday. Since the proposition you claim to know has to be true for you to know it, this suffices to establish that you didn’t know on Sunday that it would rain Monday. So it wasn’t a problem with the weak sense of knowledge that made us say on Sunday that you know it would rain Monday and then take it back the next day. Rather, you never knew it would rain Monday, but we all learned that this was so on Monday when it didn’t rain. According to Hospers, then, good evidence is still good even if the proposition it supports doesn’t turn out to be true.

Second, Hospers argues that the strong sense of knowledge is meaningless. As he sees it, the strong sense demands that S be certain of P, and this is meaningless if there aren’t any circumstances in which one could be certain of P. As far as I can tell, however, he doesn’t argue that there aren’t any circumstances in which one could be certain of P. Instead, he gives us the story about appendicitis and says things like: “Can you describe to the circumstances in which you would say it’s certain? If you can’t, then the phrase ‘being certain’ has no meaning as you are using it.” (225) If the use of ‘certain’ in the strong sense of “know” is indeed meaningless, then we would have grounds for rejecting skepticism, but can you find any argument for the claim that the use of ‘certain’ is meaningless in the strong sense of “know”? If you can, post it on the course discussion board. Alternatively, you might try to figure out whether Descartes can answer Hospers’s question above—can Descartes describe circumstances in which he’d say some P is certain?