Darwin wrote that he had “thought much about religion,” and in his typical telegraphic writing style, he speculated that “thought (or desires more properly) being hereditary” might be “a secretion of the brain.” If this were true, he continued, “it is difficult to imagine it [belief in God] anything but structure of brain hereditary … love of deity effect of organization.” Thus, thoughts, desires, and “love of deity,” he speculated, were all products of our brain organization.
