To all these arguments, indeed, I have no answer, but at length I am forced to admit that there is nothing of all those things I once thought true, of which it is not legitimate to doubt and not out of any thoughtlessness or irresponsibility, but for sound and wellweighed reasons; and therefore that, from these things as well, no less than from what is blatantly false, I must now carefully withhold my assent if I wish to discover any thing that is certain.