I have the following rough outline of utilizing solipsism as a proof by contradiction to the goal of asserting an epistemological proof of the external world.
- A solipsist (Wittgenstian) lives in a world full of certainty.
- Epistemologically, a solipsist self is one and the same with the world, leaving no room for doubt in such a world.
- A solipsist cannot doubt and live in a world full of certainty.
- Where doubt arises, the world is not solipsistic.
- Therefore doubt presupposes a world where epistemologically one can find out new facts or experiences about the world.
- Hence, where doubt arises, the existence of an external world that is non-solipsistic is warranted to assume and/or conclude.
My question is providing grounding for both claims 1 & 3. Can anyone point me towards some reputable literature that would support these seemingly obvious, yet, profound in scope and brevity claims? I had thought that something from the Tractatus, where Wittgenstein talks about solipsism as useful; but, the stipulation of solipsism by Wittgenstein in the Tractatus of the term 'solipsism' goes quite deep down the rabbit hole, quite fast.
Any help appreciated.