(8) The sentiment of parent love having been called into existence by the aid of the factors we have already enumerated—directly in the case of 1 and 2, more indirectly in the case of 4, 5 and 6 and still more indirectly perhaps in the case of 3 and 7—all conditions are particularly favourable for its The sentiment of parent-love is powerful in virtue of its early formation continuance and growth. In the first place, it is almost certainly one of the earliest important sentiments to be formed, the only other one which can compare with it in this respect being the self-regarding sentiment. It thus enjoys as compared with most others sentiments all the advantage afforded by priority. What the exact nature of any such advantage may be, it would be hazardous to suggest in detail: we know however that it is a general characteristic of the function and development of mind that dispositions which are formed early in the life of the individual enjoy a greater stability and permanence than those subsequently acquired. Even where, as so often happens, the function of the earlier dispositions is modified or obscured by the results of later experience, the phenomena of "regression" to earlier levels, as manifested in pathology, show clearly enough that the earlier dispositions remain intact throughout life and in many cases seem to be (in themselves and apart from the influence of extraneous factors) paths that offer less resistance to the passage of emotional energy than do those formed at a later period. It may well be then that its priority of formation gives to the sentiment of parent-love a more stable and deep-rooted foundation than that enjoyed by any sentiment subsequently formed.
Further, psycho-analytic study appears to indicate very strongly that it is in the nature of the mind for all the earliest channels of conative energy not only to remain capable of functioning in later life, but actually to continue to function, though often in such a degree or in such a way as to have but little if any direct influence on consciousness or action. Thus it would appear that when a sublimation is formed and emotional energy is directed into a fresh channel, not all the energy passing through the original channel is deflected; some, on the contrary, continues to pass along the original channel. At each fresh sublimation this process is repeated, so that, to use a simile of Freud's, we may compare the development of the Libido to the history of a wandering tribe, which at each fresh migration leaves some of its members behind in the home it is just leaving (the larger the proportion of the population that is left behind—i. e. the greater the fixations—the greater being of course the tendency to regress along the former line of advance when an obstacle is encountered). In such a system of function and development, it is clear that the oldest channels are necessarily, in a sense, the most stable and permanent, the least easy to modify or to destroy.
In this respect then the channels comprising the sentiment of parent-love are comparable to all other early channels of the Libido. Just as the autoerotic trends connected with the oral, anal and urethral regions of the body and the primitive tendencies to sadism, masochism and exhibitionism have been shown to underlie many of the activities of adult life, so (on a higher and more complex level of development) parent-love has been revealed as the foundation upon which rests the greater part of the affection of childhood, adolescence and maturity. From this point of view it would appear that parent-love, in its persistence and influence on later life, exhibits characteristics which are, in greater or less degree, common to all the earliest manifestations of the Libido.
In one important respect however the history of parent Furthermore, numerous influences favour its persistence love differs from the history of many other of these early manifestations. Parent-love not only comes into being at a very early age, but, as regards many of its attributes, it normally persists with but little alteration throughout the whole of the impressionable period from infancy to adolescence. The sensual elements of this love are, it is true, for the most part repressed soon after they appear, but the elements of tenderness and veneration usually remain and build up a sentiment which operates vigorously and continuously for many years, whereas the other sentiments formed during this period (with the exception again of the self-regarding sentiment) are apt to be of a far more temporary and evanescent character. It is true, as we have seen, that as development proceeds the affection felt towards the parents is to some extent displaced on to other persons, but nevertheless, in the normal course of events, a large portion of this affection remains throughout early life fixated on its original object. Moreover as regards this fixation of affection on the parents (provided only no sensual element be too apparent), the individual meets as a rule with every encouragement and sign of approval from those about him, not with the disapprobation or ridicule which he often encounters when his affections are directed elsewhere. The sentiment of parent love has therefore the support of moral sanction in a way enjoyed by few, if any, other sentiments of love that may be formed in early life.
We see therefore that both as regards priority of formation and as regards duration, vigour and continuity of function throughout the all important period of development, parent love normally occupies an almost unique place among the sentiments—a place which renders to some extent intelligible the importance of the role it plays in human life.
(9) Finally, the tendency to incestuous direction of affection, The tendency to incest thus brought about is strengthened by practice and tradition having once been brought into existence, has no doubt been strengthened and consolidated by the actual practice of incest that has pretty certainly occurred on a wide scale among certain races and at certain levels of development[229].
Apart from the actual observation of incestuous practices The occurrence of incest may also be inferred from certain practices and institutions at the present day, the previous occurrence of incest on a wide scale may (as we have already to some extent indicated in earlier chapters) frequently be inferred with some degree of certainty from the nature of practices, customs, observances and institutions which seem to be remnants or vestiges of a one-time general prevalence of incest. We have already referred to the practice of brother-sister marriage among certain lines of monarchs (p. 91), to the customs of the levirate and sororate (p. 93) and of group marriage (p. 90), the droit de seigneur (p. 143) and the licence frequently permitted at certain festivals such as initiation (p. 89).
Evidence for the previous existence of incest is also forthcoming from the measures and prohibitions erected to prevent it. The "avoidances" practised by a large number of savage peoples are very numerous and have reference to all the principal relationships, both those of blood and those acquired by marriage. These "avoidances" are unhesitatingly regarded by most authorities as customs adopted as a precaution against incest.