the real science of physiology he has not touched, has not dreamed of; nor have any of his brethren who see in the human soul only a useless appendage to the body. The soul is the _forma corporis_, its informing, its vital principle, and pervades, so to speak, and determines, or modifies, the whole life and action of the human body, from the first instant of conception to the very moment of death. The human body does not exist, even in its embryonic state, first as a vegetable, then as an animal, and afterward as united to an immaterial soul. It is body united to soul from the first instant of conception, and man lives, in any stage of his existence, but one and the same human life. There is no moment after conception when the wilful destruction of the foetus is not the murder of a human life. As we said on a former occasion, or at least implied, man, though the ancients called him a microcosm, the universe in little, and contains in himself all the elements of nature, is neither a mineral nor a vegetable, nor simply an animal, and the analogies which the physiologist detects between him and the kingdoms below him, form no scientific basis of human physiology, for like is not same. There may be no difference that the microscope or the crucible can detect between the blood of an ox and the blood of a man; for the microscope and chemical tests are in both cases applied to the dead subject, not the living, and the human blood tested is withdrawn from the living action of the soul, an action that escapes the most powerful microscope, and the most subtile chemical agent. Comparative physiology may gratify the curiosity, and, when not pressed beyond its legitimate bounds, it may even be useful, and help us to a better understanding of our own bodies; but it can never be the basis of a scientific induction, because between man and all animals there is the difference of species. {157} Comparative physiology is, therefore, unlike comparative philology; for, however diverse may be the dialects compared, there is no difference of species among them, and nothing hinders philological inductions from possessing, in the secondary order, a true scientific character. Physiological inductions, resting on the comparative study of different individuals, or different races or families of men, may also be truly scientific; for all these individuals, and all these races or families belong to one and the same species. But the comparative physiology that compares men and animals, gives only analogies, not science.