Since the Renaissance Stoic ethics and some aspects of the stoic view of nature have attracted those who have found it impossible either to accept Christianity or to lapse into complete atheism. The Stoic sage’s sense of duty, his concern for others, his constancy, his independence of external conditions, and his freedom from irrational impulses have offered a secular moral that has influenced philosophers as different as Spinoza, Hume, and Kant.
Still, though Stoicism has appeared to be an alternative to Christianity, it has also influenced the development of Christian doctrine. Christian thinkers wanted to show that natural reason laid a foundation for faith; and to show this they turned naturally to the Stoic view of the cosmos as an ordered whole, guided by an immanent law, and manifesting a divine intelligence. Saint Paul argues on Stoic grounds that the gentiles had some access to the nature of God. For the Stoic, as for the Jew and the Christian, it was true both that “the heavens declare the glory of God”, and that the law of the Lord is perfect. Much of Stoic natural religion, therefore, was incorporated into Christian defences of faith, addressed to non-believers.
Similarly, Stoic ethics showed how someone might live his life with integrity and concern for others, without devoting himself to worldly success or rewards from society. In Stoic ethics Christians could see how to be unworldly, without being indifferent to the state of the world or to the practices and institutions needed to maintain a human community. For these reasons Stoic ethics came to be included in expositions of Christian ethics. Through these influences on Christianity, Stoic ideas came to guide some of the thoughts and actions of people who would have been wholly untouched by a purely Philosophical movement.