This is a philosophical question that many philosophers including Kant, Russell, Wittgenstein, Dennett and others have attempted to answer. Essentially solipsism asserts that the only thing that we can be sure to exist is ourself. In other words, the world is a “dream” and all are perceptions of an outside world are illusions. Consequently, we cannot refute solipsism by observation of external events (empiricism) because it contradicts our assumption that there is no outside world.
Russell tried to refute solipsism using logic (Occam’s Razor), Wittgenstein by suggesting it was an “illegitimate” paradox of language, and Dennett by suggesting that language is a social instrument derived from connections outside oneself, so the question implies external existence.
My field is mathematics, and when I study these philosophers, I find my view is most closely aligned with Russell’s. I believe that you have no way of proving that you are not the only one alive. You may indeed, be the only one who exists and everyone else may be a figment of your imagination. However, it’s a more practical assumption to proceed with the idea that there is an external world, because I know that I exist and therefore, you are not the only person who exists, but then you may be a figment of my imagination.
The bottom line is that we’re all confined within our own minds and the only thing an individual knows for sure is that he exists. (I can’t say “he” or “she”, because that would imply the existence of more than one possibilities.) As Descartes asserted, “I think, therefore I am.” That’s the only thing of which we can be certain.
I find it entertaining to think about such things, because I am the only being that exists, or am I merely a figment of your imagination?😀
