We must remember, moreover, that there are more definite grounds for the subordination of modesty with the development of civilization. We have seen that the factors of modesty are many, and that most of them are based on emotions which make little urgent appeal save to races in a savage or barbarous condition. Thus, disgust, as Richet has truly pointed out, necessarily decreases as knowledge increases.[73] As we analyze and understand our experiences better, so they cause us less disgust. A rotten egg is disgusting, but the chemist feels no disgust toward sulphuretted hydrogen; while a solution of propylamin does not produce the disgusting impression of that human physical uncleanliness of which it is an odorous constituent. As disgust becomes analyzed, and as self-respect tends to increased physical purity, so the factor of disgust in modesty is minimized. The factor of ceremonial uncleanness, again, which plays so urgent a part in modesty at certain stages of culture, is to-day without influence except in so far as it survives in etiquette. In the same way the social-economic factor of modesty, based on the conception of women as property, belongs to a stage of human development which is wholly alien to an advanced civilization. Even the most fundamental impulse of all, the gesture of sexual refusal, is normally only imperative among animals and savages. Thus civilization tends to subordinate, if not to minimize, modesty, to render it a grace of life rather than a fundamental social law of life. But an essential grace of life it still remains, and whatever delicate variations it may assume we can scarcely conceive of its disappearance. In the art of love, however, it is more than a grace; it must always be fundamental. Modesty is not indeed the last word of love, but it is the necessary foundation for all love's most exquisite audacities, the foundation which alone gives worth and sweetness to what Sénancour calls its "delicious impudence."[74] Without modesty we could not have, nor rightly value at its true worth, that bold and pure candor which is at once the final revelation of love and the seal of its sincerity. Even Hohenemser--who argues that for the perfect man there could be no shame, because shame rests on an inner conflict in one's own personality, and "the perfect man knows no inner conflict"--believes that, since humanity is imperfect, modesty possesses a high and, indeed, symptomatic value, for "its presence shows that according to the measure of a man's ideal personality, his valuations are established."