Doubt is not a pleasant state of mind, but certainty is absurd – Voltaire.
From the early days of Greek philosophy to the middle ages there was no distinction between Philosophy and Theology. All efforts were devoted to understanding the nature of God and with various “proofs” of His existence. The duality of the body and mind allowed for the concept of the soul to be taken for granted.
Along came philosophers like Hobbes, Descartes and Spinoza who began to liberate philosophy from theology. Kant separated them completely by destroying the long established theological “proofs” (I hate the term as they were never proof of anything) for the existence of God(s) with his “Critique of Pure Reason”.
Today Philosophy, like the Sciences, is only ever a secular endeavor and has no concern for any lingering ideas from the Middle Ages. Only those who engage in magical thinking consider that mind and body duality is still worthy of investigation. They only do so because giving up on that notion would mean giving up on the idea of having a soul and that would mean admitting they will not become immortals. Ergo no god! They would have to consider that morality is founded on sociology rather than theology. They often wonder aloud how atheists can be moral and I wonder how weak they are to need an ancient tome to get theirs. Philosophy evolves by the use of Reason and this advances humanity. Theology discovers things supernaturally and leaves its followers stupefied. That is because, as Paine said, Theology is the study of nothing.
I can live with doubt and uncertainty. I think it’s much more interesting to live not knowing than to have answers which might be wrong – Richard Feynman.