Dr. McDougall goes on to show how from this emotion and its impulse to cherish and protect spring generosity, gratitude, love, true benevolence, and altruistic conduct of every kind; in it they have their main and absolutely essential root without which they would not be. He argues that the intimate alliance between tender emotion and anger is of great importance for the social life of man, for "the anger invoked in this way is the germ of all moral indignation, and on moral indignation justice and the greater part of public law are in the main founded."[11] The reader may be earnestly counselled to acquaint himself with Dr. McDougall's book, which, in the judgment of those best qualified, definitely advances the science of psychology in its deepest and most important aspects. _The Transmutation of Instinct._--The last thing here meant by the transmutation of instinct is that by any political alchemy it is possible--to quote Herbert Spencer's celebrated aphorism--to get golden conduct out of leaden instincts. But it is the mark of man, the intelligent being, that in him the instincts are plastic, and even capable of amazing transmutations. In the lower animals there is instinct, but that instinct is an almost completely fixed, rigid, and final thing. In ourselves there is a limitless capacity for the development, the humanization of instinct along many lines, as when the primitive infantile curiosity works out into the speculations of a thinker. In other words, _we_ are educable, the lower animals are not, or only within very narrow limits. Yet in one respect the lower animals have the advantage over us. Their instincts are often perfect. We cannot teach a cat anything about how to look after a kitten; but parallel instincts amongst ourselves, though not less numerous or potent, are not perfected, not sharp-cut. In the cat there is no need for education; in woman there is eminent need for it. Indeed it is the lack of education that is largely responsible for our large infant mortality; not that woman is inferior to the cat, but that, being not instinctive but intelligent, she requires education in motherhood. Human instincts in general are capable of modification; sometimes they may take bizarre forms, and so we find that there are people without children of their own--more commonly women--who will have twenty cats in the house and look after them, or who will devote their whole lives to the cause of the rat or the rabbit, or whatever it may be, while the children of men are dying around them. These things are indications of the parental instinct centred on unworthy objects. It is a common thing to laugh at these aberrations--thoughtlessly, may we not say? While orphans are to be found, we should do better if we try to bring together the woman who needs to "mother" and the child who needs to be "mothered."