There is also in us an instinct of pugnacity, which especially appears when the working of any other instinct is thwarted. We know that the parental instinct when thwarted, as in the tigress robbed of her whelps, shows itself in pugnacity--even in the female, which commonly has no pugnacity; and in the emotion of anger. It is a reasonable supposition that the fine anger, the passion for justice, the passion against, say, slavery or cruelty to children--that these indignations which move the world are at bottom traceable to the workings of the outraged parental instinct. When we have tender emotion towards a child, or towards an animal, whatever it be, this is really the subjective side of the working of the parental instinct. Now, tender emotion is what has made and makes everything that is good in the individual, and in human society. It is the basis of all morality--all morality that is real morality--everything that permits us to hold up our heads at all, or to hope for the future of the race. That is why the study of the parental instinct, its correlate or source, is as important and serious as any that can be imagined. Let us begin by a quotation from Dr. McDougall, author of the best and most searching account of this instinct yet written:-- "The maternal instinct, which impels the mother to protect and cherish her young, is common to almost all the higher species of animals. Among the lower animals the perpetuation of the species is generally provided for by the production of an immense number of eggs or young (in some species of fish a single adult produces more than a million eggs), which are left entirely unprotected, and are so preyed upon by other creatures that on the average but one or two attain maturity. As we pass higher up the animal scale, we find the number of eggs or young more and more reduced, and the diminution of their number compensated for by parental protection. At the lowest stage this protection may consist in the provision of some merely physical shelter, as in the case of those animals that carry their eggs attached in some way to their bodies. But, except at this lowest stage, the protection afforded to the young always involves some instinctive adaptation of the parent's behaviour. We may see this even among the fishes, some of which deposit their eggs in rude nests and watch over them, driving away creatures that might prey upon them. From this stage onwards protection of offspring becomes increasingly psychical in character, involves more profound modification of the parent's behaviour, and a more prolonged period of more effective guardianship. The highest stage is reached by those species in which each female produces at a birth but one or two young, and protects them so efficiently that most of the young born reach maturity; the maintenance of the