In the first stage of his career, Robert C. Solomon turned from a broadly rationalist orientation in philosophy to a focus on the centrality of emotion in human life. His early works already reveal a tension between the traditional dominance of reason in Western philosophy and his growing conviction that the passions are indispensable to understanding human existence. From Rationalism to Existentialism (1972) situates existentialist thought as a response to rationalist traditions, emphasizing freedom, responsibility, and subjective experience. The Passions (1976; paperback 1977) represents a decisive turn, offering a systematic analysis of emotions as meaningful, intelligible, and integral to our lives rather than irrational disturbances. Finally, History and Human Nature (1979) demonstrates Solomon’s interest in situating philosophical accounts of human agency within historical and cultural contexts. Together, these works mark Solomon’s move from rationalist concerns to a pioneering exploration of the philosophy of emotion.