As a university professor and independent scholar, Gregory has published over fifty articles and edited four book-length works.

He's written on Catholic social thought, ethics and economics, Christian humanism, human sexuality, Ireland, and the relationship between religion and culture. 

In 2020, he launched the Oran Mor Project, an ongoing series of essays responding to the crisis of meaning in Western culture.

He explores possible solutions influenced by metamodernism, emergent theory, liberal naturalism, Celtic spirituality, and the Christian tradition.