The Expression of the Emotions in Man and Animals usually been viewed in its relationship to Darwin's conception of "natural selection" as the central mechanism of evolutionary development, which he probably grasped some time around September 1838. These notes have a tentative and fragmented quality, especially in Darwin's descriptions of conversation with his father (a successful doctor with a special interest in psychiatric problems) about recurring patterns of behaviour in successive generations of his patients' families. Darwin was anxious about the materialistic drift in his thinking – and of the disrepute which this could attract in early Victorian England – at the time, he was mentally preparing for marriage
The Constitution of Man Supremacy of the Moral Sentiments and Intellect," Combe goes on to argue that the moral sentiments are superior to those that men share with animals, and that the faculties "are right only when directed by "enlightened" intellect and moral sentiment..."they must be illuminated by knowledge of science and of moral and religious duty,"" or else the result is evil. A delicate balance of the expression of the faculties is required for man's happiness. In Section five, "The Faculties of Man Compared with External Objects," Combe identifies specific faculties and their effects on the eternal world. For example, with Philoprogenitiveness, the