How, or why is it we can assert individually "I exist"? Descartes considered this problem wasn't answerable or perhaps didn't understand it like we (think we) do now. Can an individual assert "I am, therefore, I think"? Who asserts thought, in that case, or where do thoughts occur and why? We assert that individuals thought of things, or discovered otherwise hidden structures in nature, which have always been there. But no single individual can "think by themselves", the will to think comes from our collective "duty" to do so, as Spinoza would have er, thought of it.