In his book on Wittgenstein and ethics, Olafson briefly sketches a wonderful criticism of the solipsistic position that we cannot be sure of the existence of other minds. The existence of other minds, Olafson writes, is a precondition of our ability to think and argue about things like the existence of other minds. In fact, the fact that we have debates on solipsism is in one sense inherently surreal. Imagine a group of philosophers debating with each other in conferences, sending emails and writing papers, taking into account each other’s ideas, and so on – on the topic of whether those people with which they are collaborating really exist.
This kind of doubt, Olafson suggests, is a mistake that reflects a problem with your philosophical approach. It’s impossible to genuinely doubt the existence of other people since, as Wittgenstein argues at length, our own existence is inextricably bound up with that of others. We exist as Mitsein, being-with, and so on. It is impossible to be a person alone.