To be ever upright and to be worthy of one's good blood, this was the simplest, most obvious and most imperious duty. It would have been very difficult for Jefferson to believe any longer that "at the end of the journey we shall deliver up our trust into the hands of him who gave it and receive such reward as to him shall seem proportionate to our merit", which was his belief in 1763. There was not even much to obtain in our life as a reward, for most societies are so organized that "whenever a man is noble and zealous, he wins no higher prize than baser men."[18] Still the fact remained that, after the collapse of all the religious superstructure, the foundations of morality were left unshaken, so Jefferson undertook to rebuild his own philosophy of life according to Bolingbroke's advice, with the material at hand. For it was evident that "a system thus collected from the writings of ancient heathen moralists, of Tully and Seneca, of Epictetus, and others, would be more full, more entire, more coherent, and more clearly deduced from unquestionable principles of knowledge."[19] But he would take nobody's word for it, he would accept the teachings of no professor of moral philosophy; every man had to think for himself and to formulate once for all his own philosophy. When writing to his nephew, who he thought might go through the same crisis, Jefferson declared some forty years later that: Man was destined for society. His morality, therefore, was to be formed to this object. He was endowed with a sense of right and wrong, merely relative to this. This sense is as much part of his nature, as the sense of hearing, seeing, feeling; it is the true foundation of morality and not the TO KALON, truth, etc. as fanciful writers have imagined. The moral sense, or conscience is as much a part of man, as his leg or arm.