We have shown in the preceding investigation that the control of the sexual passion and its guidance by Reason--which we name Virtue--is of fundamental importance; that it is essential to individual health, to the happiness of the family, to the purity of Society, and the growth of a strong nation. Virtue, therefore, is desirable. It remains to consider whether it be practicable. No vagueness or doubt should exist in relation to fundamental principles of education. Methods may change; no inflexible rule can be laid down. Enlarging experience, enlightened by love, will vary infinitely the adaptations needed in the education of infinitely varied children, but the aim of education should not vary. Sound knowledge, as well as a steadfast faith and hope, must guide every intelligent parent from the beginning of family life, or confusion, perplexity, and endless difficulties will be added to the inevitable difficulties of education. One of the most serious questions to be understood and practically answered by parents in the education of their sons is this: If in relation to sex Chastity be the true moral aim of a young man’s education, can it be secured without injury to his health? Is morality an advantage to the health of young men?[32] It is impossible to over-estimate the importance of this question, both to men and women. It touches the most vital interests of both. The family, the relations of husband and wife, the education of children, the rules and customs of society, and the arrangements of practical life will directly depend upon, or be affected by, the answer which we give to the question, Is virtue an advantage to all human beings? Can one moral law exist for all? Truth must always be accepted. No personal prejudice, no habit of education, must stand in the way of clearly established truth. It is the greatest sin we can commit to try to believe a lie because the truth seems unpleasant, difficult, or contrary to prejudices. If it be true that chastity is a right thing for women, but a wrong thing for men, then the truth, with all its consequences, must be accepted. If, however, this statement be false--if it be a prejudice of education, a result of evil customs, the most fruitful source of misery to the human race--then the truth, with all its consequences, must equally be accepted. In seeking truth on this subject it is indispensable to examine its practical aspect closely, to study the facts on which existing customs are based, and disentangle the confused web of truth and falsehood, out of which has grown the present widespread belief that a young man cannot lead a chaste life to the age of twenty-five without injury to his health.