Lucien Greaves is an American activist and co-founder of the Satanic Temple, an organization that promotes secularism and social justice. He is known for his efforts to advocate for the separation of church and state, often using provocative campaigns to challenge religious privilege in public spaces. Greaves has also been involved in various legal battles and public demonstrations, aiming to highlight issues such as religious discrimination and freedom of expression. His work often emphasizes the importance of reason and compassion, positioning the Satanic Temple as a non-theistic alternative to traditional religious practices.