Which ideas did Seneca borrow from Stoicism?

Seneca the Younger was a prominent practitioner of Stoicism, though his philosophical works represent an eclectic version of middle Stoicism rather than a rigid adherence to the school's original doctrines. His thought was heavily influenced by the adaptations of earlier thinkers such as Panaetius and Poseidonius, who tailored Stoic precepts for the Roman aristocracy.12

Key Stoic concepts integrated into Seneca’s writings include:

• The Life of Virtue: Like other Stoics, Seneca maintained that virtue is the only true good and that external circumstances—such as wealth, health, or social status—are ultimately indifferent.21
• Living According to Nature: He emphasized the Stoic goal of aligning human existence with the rational order of the universe, or the divine logos.21
• Control of Passions: Seneca explored the nature and control of emotions, particularly in his work De ira (On Anger), viewing unchecked passions as errors in judgment that deviate from duty and reason.21
• Moral Duty and Composure: His writings, such as the Moral Letters to Lucilius, focus on practical moral problems, advocating for fortitude, mental tranquility, and the steadfastness of the wise person in the face of adversity.1