I think, and this or that the cogito thought appears to me as true; I am well aware that it is not unconditionally true, and that the process of making it totally explicit would be an endless task; but the fact remains that at the moment I think, I think something, and that any other truth, in the name of which I might wish to discount this one, must, if it is to be called a truth for me, square with the 'true' thought of which I have experience.