See part 1
We can do metaphysical solipsism first, and if you are about it, the argument goes roughly as follows: 1) your mind is the only thing that you have access to, 2) confirmation of mind outside one’s mental state is impossible, 3) therefore only your mind exists. The kernel of the argument is that there is simply no link between our mental state and the truthfulness of the existence of other minds, or if you will, the existence of other minds as such (granting the deflationary position) – including the subject with the mind. As such a metaphysical solipsist will be fine with the following statement: “Trump does not exist.” “The fellow who is reading these words do not exist,” only their appearances do. etc. etc.
I think solipsism is very silly, but of course that is not an argument, you need an argument to kill these things. It reminds me of the story of a fellow who upon sighting a couple (huge) cockroaches on his bed, proceed to profess how much of a nuisance the roaches are, and stopped there. As if to say calling roaches nuisances – which they are if they inhabit your bedroom – would exterminate them. So here you go: 1) there are no evidences of a private language. (A private language is a language which you solely develop and use, not a code that can be deciphered by another agent, but a language woven into your thoughts.) 2) You communicate with people with a shared language. 3) If there are shared languages, other minds are needed for its use and evolution. 4) Therefore, other minds exist.
Let’s say that wasn’t convincing enough, you don’t buy it, and you ask me: what if solipsism is true? It wouldn’t matter if it is. Partly because any attempt to spread the ‘gospel’ of solipsism will be granting that solipsism is false.
There is another, albeit milder version of this whole solipsism business. Let me illustrate. As I am typing these words, I can see a white paper just to my left side. And then something strikes me like a thunderbolt: “how the hell do you know this is a paper?” And what does it mean for something to be a paper?
See, forget about the label ‘paper’ for a minute and think of that which the ‘paper’ corresponds to, let’s call this thing Ð (breaking away from solipsism, we grant that Ð exists.)
The question now is, am I really seeing Ð? or is my mind processing Ð such that I see it as a paper? How could we possibly test this hypothesis? These questions can be deceptively tractable, so let me rephrase it: how do I know when I see Ð?
It turns out that if I can, 1) perceive a paper as a paper, and 2) use the paper for what a paper is used for, then it is a paper. But does that disprove the possible existence of a Ð? And so on, and so forth.
This is a classical critique of the integrity of our sense perception. But there is not much to work with here, friends. To prove the integrity of our sense perception, we would have to get out of it, except that we can’t. And since there are no defeaters for our sense perception, we are totally in good shape to trust it. And I can’t believe I just typed the last statement. However, things will become more complicated the moment we start to talk about evolution via natural selection (more on this later).
Anyways, I hope it doesn’t surprise the reader that I do believe that Trump exist. And hopefully not shocking that some folks don’t.