## Tuesday, February 06, 2018

### What do Philosophers do?

I'm half-way through Maddy's 2017 (a walk through the modern history of Skepticism), where she describes a weakness of the Argument from Dreaming: although we would not be knowing the world were we now dreaming in the ordinary way, we can rule that out in quite ordinary ways; and whereas we cannot rule out that we are dreaming in some extraordinary way (e.g. a life-long coma), why should we rule it out? Such things are unheard of! Furthermore, maybe this is a dream-world, and my hands dream-hands within it; what of it? It is far from obvious why the fact that I don't know much about the fundamental substance of my hands should get in the way of my knowing that I'm typing this with them because they exist (whether that is in a way that is to some unknown world much as dreams are to this world, or some other way).

But here's a thought: If some higher power (maybe a UFO) replaced you with a pod-person who was exactly the same as you, physically and mentally, then the people of the world would of course not know, were they to see that person before them, that you were standing there. So, if the underlying substance of the world was such that things were frequently replaced with identical copies, in such ways (and note that we cannot even know that that is unlikely), then our references would frequently fail, and we would end up knowing a lot less about the world than we assume we do. We do assume that such does not happen, but that just means that, for example, it is at best epistemic luck that people know that you are there, when they see you. At worst it is knowledge by assumption, because we do assume as much; which reminds me of Wittgenstein's "hinge propositions," which Maddy will be getting to shortly...

Perhaps we assume that things generally continue to be the same things. Or perhaps we assume that things that look the same are the same. I would not say that we know such a proposition, but maybe we do thereby know propositions that depend logically upon it, such as that I have hands. (Knowledge seems not to be some minimal amount of epistemic luck, but rather the sufficient reduction of certain kinds of epistemic luck, as required by one's context; and philosophy is a context with high standards. In philosophy we tend to accept the force of epistemic closure, because the high standard is logic (or meta-logic).)