Paul Tillich (1886–1965) was one of the most important theologians of the twentieth century, known for his proposals of systematic theology, the existential accent and the correlation method. However, his philosophy of religion is not routinely considered, despite the fact that he wrote on this particular philosophical theme. Tillich considered himself a denizen of the border between philosophy and theology and, as such, took a liminal stance:

Tillich affirms that he feels equal passion for philosophy and theology, especially because he has consciously lived on conceptual borders all of his life, which was marked directly by World War II. For Tillich, ‘[s]ince thinking presupposes receptiveness to new possibilities, this position is fruitful for thought; but it is difficult and dangerous for life, which again and again demands decisions and thus the exclusion of alternatives’. This relationship is precisely the horizon which also marked his proposals and, in this case, will guide our interpretation of the viability of the relationship between science and religion.

Although it is not possible to identify one single work in which Paul Tillich specifically tackles the relationship between science and religion, it is possible to highlight various allusions to science or sciences in his philosophy and theology.