Again, he continually assumes that animals low down in the scale of life cannot know their own business because they show no sign of knowing ours. See his remarks on _Saturnia pavonia minor_ (page 107), and elsewhere on cattle and gadflies. The question is not what can they know, but what does their action prove to us that they do know. With each species of animal or plant there is one profession only, and it is hereditary. With us there are many professions, and they are not hereditary; so that they cannot become instinctive, as they would otherwise tend to do. * * * * * He attempts {144b} to draw a distinction between the causes that have produced the weapons and working instruments of animals, on the one hand, and those that lead to the formation of hexagonal cells by bees, &c., on the other. No such distinction can be justly drawn. * * * * * The ghost-stories which Von Hartmann accepts will hardly be accepted by people of sound judgment. There is one well-marked distinctive feature between the knowledge manifested by animals when acting instinctively and the supposed knowledge of seers and clairvoyants. In the first case, the animal never exhibits knowledge except upon matters concerning which its race has been conversant for generations; in the second, the seer is supposed to do so. In the first case, a new feature is invariably attended with disturbance of the performance and the awakening of consciousness and deliberation, unless the new matter is too small in proportion to the remaining features of the case to attract attention, or unless, though really new, it appears so similar to an old feature as to be at first mistaken for it; with the second, it is not even professed that the seer’s ancestors have had long experience upon the matter concerning which the seer is supposed to have special insight, and I can imagine no more powerful _à priori_ argument against a belief in such stories. * * * * * Close upon the end of his chapter Von Hartmann touches upon the one matter which requires consideration. He refers the similarity of instinct that is observable among all species to the fact that like causes produce like effects; and I gather, though he does not expressly say so, that he considers similarity of instinct in successive generations to be referable to the same cause as similarity of instinct between all the contemporary members of a species. He thus raises the one objection against referring the phenomena of heredity to memory which I think need be gone into with any fulness. I will, however, reserve this matter for my concluding chapters.