And yet Tolstoy is wrong in wishing to forbid this. As long as it does no actual harm we must tolerate it, the more so because the happiness of the individual and the cheerfulness with which he labours are so often dependent upon the normal satisfaction of his instincts. Within the limits indicated above, the gratification of the sexual instinct, whether in the case of man or woman, is in itself ethically indifferent, provided it does not result in the procreation of children. We have already dealt with the ethical value of procreation, which depends upon the nature of the results expected. And we are therefore bold enough to declare that every sexual connection which does not injure either of the two persons who take part in it, or any third person, and which, moreover, can do no injury to the child which may be engendered by it, is in itself ethically indifferent, and cannot therefore be immoral. We have certainly imposed considerable modifications in this sentence, for it is possible for a perfectly normal sexual connection to do untold injury, especially to the woman and the child she bears; so that an act which is in theory not immoral may become so in practice, or may give rise to grave moral conflicts. This often happens at the present time as the result of our prejudices, established customs, and unjust laws. From the standpoint of sexual ethics the ideal marriage is undoubtedly a monogamous union, resting upon mutual and enduring affection and loyalty, and consummated by the birth of several children; a union in which the husband may be from six to twelve years older than the wife, and both must be robust in mind and body. This ideal state of things is not as rare as our modern pessimists would have us believe, but neither is it especially common. Moreover, if this marriage is to reach that perfection which it can and must attain, it must be completely free, that is to say, both parties must be absolutely equal before the law, and no external compulsion other than that of common obligations towards the children must bind them to one another. To this end a complete separation of property, and a just and proper valuation of every service performed by the wife as well as the husband are of the first importance. From the aforesaid it must by no means be inferred that every person is to yield without restraint to his sexual desires. Unfortunately this fundamentally false conception of free marriage and free love is at the present time widespread, and it cannot be too vigorously combated. In the first place, two persons are concerned in the sexual act, and any exercise of constraint by one upon the other is immoral and even criminal. The same holds true of every seduction.