Abstract
That human beings have the potential for rationality and the ability to cultivate it is a fact of human nature. But to value rationality and its subsidiary character dispositions - impartiality, intellectual discrimination, foresight, deliberation, prudence, self-reflection, self-control - is another matter entirely.
I am going to take it as a given that if a person's freedom to act on her impulses and gratify her desires is constrained by the existence of others' equal, or more powerful, conflicting impulses and desires, then she will need the character dispositions of rationality to survive. The more circumscribed one's freedom and power, the more essential to survival and flourishing the character dispositions of rationality and the spirit may become.