He is a core faculty member at Pacifica Graduate Institute,[2] where he was involved in the development of the Mythological Studies program.
He later pursued advanced studies at the University of Dallas, where he obtained a second Master of Arts in Literature and Phenomenology[disambiguation needed], as well as a Ph.D. in Literature and Phenomenology in 1976 Slattery taught for 40 years in elementary, secondary, undergraduate, and graduate programs.
[7] Slattery is the author of several books including: The Idiot: Dostoevsky’s Fantastic Prince; The Wounded Body: Remembering the Markings of Flesh;[8][9] Grace in the Desert: Awakening to the Gifts of Monastic Life;[2][10] Harvesting Darkness: Essays on Literature, Myth, Film and Culture and A Limbo of Shards: Essays on Memory, Myth and Metaphor.
He is also the author of three volumes of poetry: Casting Shadows; Just Below the Water Line; and Twisted Sky.
With Glen Slater, he has co-edited Varieties of Mythic Experience: Essays on Religion, Psyche and Culture.