This work details the life of Alexandrian Jewish philosopher Philo and his guidance on the conduct of the spiritual life, with an introduction surveying the life and works of Philo and the critical writing on his philosophy. To Philo, the road to blessedness is the struggle against sin, which begins with penance; then a general struggle against the passions and the world; then a double road to perfection, through knowledge and askesis, "practice, training, asceticism"; To Philo, the result is in the perfection of knowledge in the divine vision, and perfect wisdom. Readers interested in Jewish mysticism and philosophy will find this an especially worthwhile read.