This chapter discusses Michael Polanyi's incentive for the publication of his Personal Knowledge: Towards a Post-Critical Philosophy of Science, which was an invitation to give a set of Gifford Lectures at the University of Aberdeen. The mandate of the lectures is one of discussing natural religion or natural theology as knowledge “without reference to or reliance upon any supposed special exceptional or so-called miraculous revelation.” The lectures and their revision in Personal Knowledge owed a considerable debt to the philosopher Marjorie Grene, who worked with Polanyi as his assistant and critic throughout the 1950s. The multifaceted origins and audiences for the book in its religious, political, humanistic, and sociological dimensions are demonstrated in the names of those whom Polanyi asked to read the manuscript: the Christian ecumenist J. H. Oldham, the neoconservative journalist Irving Kristol, the poet and novelist Elizabeth Sewell, and the sociologist Edward Shils.