Everyone who observes himself doubting observes a truth, and about that which he observes he is certain; therefore he is certain about a truth. Everyone therefore who doubts whether truth exists has in himself a truth on which not to doubt.... Hence one who can doubt at all ought not to doubt the existence of truth.
Satisfy yourself beyond all doubt that you are qualified for the course to which you now aspire.....and try to achieve something in your own land before you venture on a strange one.
Women are quite able to make friends with a man; but to preserve such a friendship - that no doubt requires the assistance of a slight physical antipathy