How the dispositions were acquired in cases where they are not hereditary, though a most interesting and important inquiry, and one upon which the old Egyptians would have had a great deal to tell us, is not material to the point now before us. In whatever way the dispositions may have been acquired, the feelings and acts resulting from them are instinctive. As a matter of fact, instincts may be acquired in many ways, as, for instance, through the action of fear, hope, law, religion, training, and even of imitation. A generalization which would include far the greater part of these causes is one I have already frequently used—that of the working of society. Perhaps still more of them may be summed up in the one word knowledge. What a man knows is always present to him, and always putting constraint upon him, disposing him to act in one definite way, conformably to itself, and regularly, instead of in any one of ten thousand other possible ways. This, sooner or later, issues in the habit which is inchoate instinct, and at last in the instinct which is hereditary habit. The hereditary habit, however, is still reversible. It was just because the Egyptians observed a multitude of these social, family, and self-regarding instincts in the lower animals, who possessed each those necessary for itself, without the aid of speech or law, or other human manifestations of reason, that they made them the symbols of the attributes of divinity. That they had designedly studied the whole of this subject of instinct carefully and profoundly, and that their study of it had been most successful and fruitful, are as evident to us at this day as that they built the Pyramids and Karnak. We see the attractiveness the study had for them in the fact that they had trained cats to retrieve wounded water-fowl, and lions to accompany their kings in war, and assist them in the chase; and that they recorded in their sculptures and paintings that they had thus triumphed over nature, obliterating her strongest instincts, and implanting in their place what they pleased. This tells us, as distinctly as words could, the interest they took in the subject, and the importance they attached to it; and that they had formulated the two ideas, first that instincts can be created and reversed, and then that everything depends upon them. All this had been consciously thought out, and worked out by them; and was as clear to their minds as the axioms of political economy are to our modern economists.