system
Given the following post, respond as if you're commenting on Reddit:
human
What is Soul and why people believe in it?

I know the "Floating Man" by avicenna (I remember the idea, but not the names), Descartes's "cogito ergo sum" also hinted this idea. And then we got Will from Schopenhauer and Nietzche, Form by Plato, Soul by Christianity, Self from Buddhism, and Being from Heidegger. I don't understand Hegel yet so I don't think I can confidently include Spirit in this list. Are all of them refer to the same thing (I think Heidegger's Being is more about the self-being-in-the-present than the immaterial being)? We see cartoon do the visualization of spirit or soul all the time, but is this visualization correct (I think of Tom and Jerry at this time of writing)? Why people believe in it? I guess its a prerequisite for the idea persistence of life after death, afterlife, and finally free will, so that's make it important. But is there any extra reason beyond it? Does compatibilist (as per my understanding, in which determinism is compatible to free will) believe in it because it enable the notion of free will, or does they believe the notion of free will is divorced from the idea of souls?

It's beyond the scope of this post, but I would also want to extend the question into, is it possible to prove or disapprove the existence of Soul?
gpt
These ideas shouldn't be thought of as the same across different philosophers/philosophies. For instance, while a Cartesian 'soul' is defined by immateriality, it's not so clear that other depictions of, for example, 'Will', are meant to be thought of in exactly the same way. For instance, a post-Kantian idea of 'pure willing' is often linked inherently with the material. For example, for Fichte, willing is only possible within materiality -- we need a realm of material things to strive for and against, otherwise there could be no striving at all. And Heidegger, for example, (I think - it's been a while) took this line of thought even further and wanted to dismantle the distinction between an immaterial 'inner' self and the world, thus 'being-in-the-world'. So to think of his account as presenting something like a 'soul' is to beg the question against him and to presuppose the very picture that he's trying to dismantle.

The reasons these philosophers believed in these different things can be answered in two possible ways: either (A) by referring to the philosophers' systems and metaphysics that gave rise to them, or (B) by referring to what (practically, socially, politically) prompted these philosophers to develop these systems in the first place. To answer only with (B) is to be perhaps unfairly historicist regarding these philosophers' beliefs, implying that they didn't *actually* believe what they believed for metaphysical/argued reasons.

I would also say that 'cartoon' visualisations of the soul are very clearly mistaken if we're referring to what many of these philosophers were on about. Whether we're talking about an 'immaterial consciousness' or 'pure will' (two different ideas, but which we can say the same thing about here) there is no possibility for visualisation. To try and depict these ideas in themselves as existing *within* space and time and as having extension (e.g. a clouded figure, or something) is to completely misrepresent what it is for something to (supposedly) be *im*material, or to be the *condition* or *ground* of such materiality.

The only way to really understand what each of these ideas mean is to learn about the philosophers' different systems that give rise to belief in them.