*119* XXXIII. There is one class of people that is very rarely met with: it is composed of those who are endowed with marked natural ability, or exceptional advantages of education and culture, or both, and who also have time to consider carefully what career in life they prefer to follow; and in this deliberation the decision must turn wholly upon each individual's natural bent. #(4) natural bias.# For we try to find out from each one's native disposition, as was said above, just what is proper for him; and this we require not only in case of each individual act but also in ordering the whole course of one's life; and this last is a matter to which still greater care must be given, in order that we may be true to ourselves throughout all our lives and not falter in the discharge of any duty. *120* But since the most powerful influence in the choice of a career is exerted by Nature, and the next most powerful by Fortune, we must, of course, take account of them both in deciding upon our calling in life; but of the two, Nature claims the more attention. For Nature is so much more stable and steadfast, that for Fortune to come into conflict with Nature seems like a combat between a mortal and a goddess. If, therefore, anyone has conformed his whole plan of life to the kind of nature that is his (that is, his better nature), let him go on with it consistently--for that is the essence of Propriety--unless, perchance, he should discover that he has made a mistake in choosing his life work. #Change of vocation.# If this should happen (and it can easily happen), he must change his vocation and mode of life. If circumstances favour such change, it will be effected with greater ease and convenience. If not, it must be made gradually, step by step, just as, when friendships become no longer pleasing or desirable, it is more proper (so wise men think) to undo the bond little by little than to sever it at a stroke. *121* And when we have once changed our calling in life, we must take all possible care to make it clear that we have done so with good reason.