Intersubjective Existence, as the author notes, aims, first, to develop a wisdom about human life that takes the form of a theory of selfhood and, second, to reflect on what is called for in the ethical practice of human existence. Secondly, the ethical implications of this theory of selfhood are explored, specifically looking at conscience, prudential reasoning, justice, friendship, the law, temperance, courage, and concluding with a brief treatment of religion.

Olivia Blanchette charts the path of his inquiry through an analysis of reflective self-consciousness in selves communing with one another. They are constituted in their substance as a union of body and soul, with intelligence and free will that give rise to cultures in communion with other selves. These cultures are over and above what is given to each self in sense consciousness and in sense appetites and which each one contends with in the exercise of selfhood and the rights that go with that in keeping with justice. Concern for right reasoning and justice leads to an analysis of temperance and courage.

The chief arguments take the form of phenomenological reflections on the building blocks of the perennial philosophy. Blanchette recasts Aristotelian-Thomistic metaphysics from the perspective of a phenomenology of the mutual recognition of agents and the historical consciousness to which it gives rise.