In the great problem of psychology we cannot expect to reach a scientific result, if we persist in restricting ourselves to the contemplation of one fact. We must avail ourselves of all accessible facts. Human psychology can never be completely resolved except through comparative psychology. With Descartes, we must inquire whether the souls of animals be relations of the human soul, less perfect members in the same series of development. We must take account of what we discover in the intelligent principle of the ant, as well as what we discern in the intelligent principle of man. Where would human physiology be, if it were not illuminated by the bright irradiations of comparative physiology? Brodie, after an exhaustive consideration of the facts, affirms that the mind of animals is essentially the same as that of man. Every one familiar with the dog will admit that that creature knows right from wrong, and is conscious when he has committed a fault. Many domestic animals have reasoning powers, and employ proper means for the attainment of ends. How numerous are the anecdotes related of the intentional actions of the elephant and the ape! Nor is this apparent intelligence due to imitation, to their association with man, for wild animals that have no such relation exhibit similar properties. In different species, the capacity and character greatly vary. Thus the dog is not only more intelligent, but has social and moral qualities that the cat does not possess; the former loves his master, the latter her home. Du Bois-Reymond makes this striking remark: "With awe and wonder must the student of Nature regard that microscopic molecule of nervous substance which is the seat of the laborious, constructive, orderly, loyal, dauntless soul of the ant. It has developed itself to its present state through a countless series of generations." What an impressive inference we may draw from the statement of Huber, who has written so well on this subject: "If you will watch a single ant at work, you can tell what he will next do!" He is considering the matter, and reasoning as you are doing. Listen to one of the many anecdotes which Huber, at once truthful and artless, relates: "On the visit of an overseer ant to the works, when the laborers had begun the roof too soon, he examined it and had it taken down, the wall raised to the proper height, and a new ceiling constructed with the fragments of the old one." Surely these insects are not automata, they show intention. They recognize their old companions, who have been shut up from them for many months, and exhibit sentiments of joy at their return. Their antennal language is capable of manifold expression; it suits the interior of the nest, where all is dark.