 Other figures played important roles in the development of natural law theory. Aristotle, with his emphasis upon reason as the distinctive human function, and the Stoics, with their emphasis upon human beings as a part of the natural order of the cosmos, both helped to shape the natural law perspective which says that “True law is right reason in agreement with nature,” as Cicero put it. Aristotle, in his approach, did allow for change to occur according to nature, and therefore the way that natural law is embodied could itself change with time, which was an idea Aquinas later incorporated into his own natural law theory. Aristotle did not write extensively about sexual issues, since he was less concerned with the appetites than Plato. Probably the best reconstruction of his views places him in mainstream Greek society as outlined above; his main concern is with an active versus a passive role, with only the latter problematic for those who either are or will become citizens. Zeno, the founder of Stoicism, was, according to his contemporaries, only attracted to men, and his thought did not have prohibitions against same-sex sexuality. In contrast, Cicero, a later Stoic, was dismissive about sexuality in general, with some harsher remarks towards same-sex pursuits (Cicero, 1966, 407-415).