"Philosophers do not carry into effect all that they teach." No; but they effect much good by their teaching, by the noble thoughts which they conceive in their minds: would, indeed, that they could act up to their talk: what could be happier than they would be? but in the meanwhile you have no right to despise good sayings and hearts full of good thoughts. Men deserve praise for engaging in profitable studies, even though they stop short of producing any results. Why need we wonder if those who begin to climb a steep path do not succeed in ascending it very high? yet, if you be a man, look with respect on those who attempt great things, even though they fall. It is the act of a generous spirit to proportion its efforts not to its own strength but to that of human nature, to entertain lofty aims, and to conceive plans which are too vast to be carried into execution even by those who are endowed with gigantic intellects....
[Seneca, De Beata Vita, ch. XX.]