He published important works on plants, animals, and natural theology.
But he was also a leading opponent of natural theology.
"Natural theology" has no value save where it leans on faith.
It formed a part of the argument from design presented by natural theology.
France had its own tradition of religious skepticism and natural theology.
Natural theology had earlier expected that scientific findings based on empirical evidence would help religious understanding.
From the late 1920s, Brunner had become increasingly interested in the question of natural theology.
Brunner, on the other hand, believed that natural theology still had an important, although not decisive, role.
The proponents of natural theology were also aware of this.
Accordingly, officials viewed direct attacks on natural theology as an abuse of free expression.