Calvin's doctrine of the calling is in part a theological response to his prior experiences and conflicts as an aspiring humanist and jurist. Calvin was deeply ambivalent to ambition (ambitio, understood as the desire for fame), as his preface, use of sources, and comments in the early humanist Seneca commentary show. He reflected on ambition and justified his own motives through a moral psychology derived from Stoicism. Although patronage was crucial for success in humanism and law, his ambivalence hampered his quest for it, and was part of a deeper discomfort with the gracious, gift-exchange element in author-patron relationships and personal friendships alike. Rather, his letters reveal, he conceived of both sorts of relationships as involving precise and rigid obligations. In his theology Calvin opposed to ambition the notion of Godly work in one's calling, implicitly rejecting the kinds of social relationships ambitio implied.