Consciousness of myself, combined with complete ignorance of everything that does not fall within my sphere of thinking, is the most telling proof of my substantiality outside God, of my original existence

We would be able neither to remember nor to reflect nor to compare nor to think, indeed, we would not even be the person who we were a moment ago, if our concepts were divided among many and were not to be encountered somewhere together in their most exact combination.

Reader! To whatever visible church, synagogue, or mosque you may belong! See if you do not find more true religion among the host of the excommunicated than among the far greater host who excommunicated them.

Revealed religion is one thing, revealed legislation, another.

The principal axiom in their theory was: Everything can be proved, and everything can be disproved; and in the process, one must profit as much from the folly of others, and from his own superiority, as he can.

Judaism boasts of no exclusive revelation of eternal truths that are indispensable to salvation, of no revealed religion in the sense in which that term is usually understood.

I fear that, in the end, the famous debate among materialists, idealists, and dualists amounts to a merely verbal dispute that is more a matter for the linguist than for the speculative philosopher