There was in Cardan's nature a strong vein of melancholy, and up to the date now under consideration he had been the victim of a fortune calculated to deepen rather than disperse his morbid tendencies. A proof of his high courage and dauntless perseverance may be deduced from the fact that neither poverty, nor the sense of repeated failure, nor the flouts of the Milanese doctors, prevailed at any time to quench in his heart the love of fame,[61] or to disabuse him of the conviction that he, poverty-stricken wretch as he was, would before long bind Fortune to his chariot-wheels, and would force the adverse world to acknowledge him as one of its master minds. The dawn was now not far distant, but the last hours of his night of misfortune were very dark. The worst of the struggle, as far as the world was concerned, was over, and the sharpest sorrows and the heaviest disgrace reserved for Cardan in the future were to be those nourished in his own household. Writing of his way of life and of the vices and defects of his character, he says: "If a man shall fail in his carriage before the world as he fails in other things, who shall correct him? Thus I myself will do duty for that one leper who alone out of the ten who were healed came back to our Lord. By reasoning of this sort, Physicians and Astrologers trace back the origin of our natural habits to our primal qualities, to the training of our will, and to our occupations and conversation. In every man all these are found in proper ratio to the time of life of each individual; nevertheless it will be easy to discern marked variations in cases otherwise similar. Therefore it behoves us to hold fast to some guiding principle chosen out of these, and I on my part am inclined, as far as it may be allowed, to say with respect to all of them, [Greek: gnothi seauton].