Scepticism is as much the result of knowledge, as knowledge is of scepticism. To be content with what we at present know, is, for the most part, to shut our ears against conviction; since, from the very gra­dual character of our education, we must continu­ally forget, and emancipate ourselves from, know­ledge previously acquired; we must set aside old notions and embrace fresh ones; and, as we learn, we must be daily unlearning something which it has cost us no small labour and anxiety to acquire