The foregoing facts illustrate fundamental physiological truths. They show the Type of creation towards which the human constitution tends and the distinctive methods of growth by which that type must be reached. In brief recapitulation, these truths are the following--viz., the slowness of human growth; the successive development of the human faculties; the injury caused by subverting the natural order of growth; the necessity of governing this order of growth by the control of Reason; the influence of Mind--_i.e._, Thought, Emotion, Will--on the development or condition of our organization; the necessity of considering the dual character of sex; the transmission of qualities by parents to their children; the natural equality in the creation of the sexes. These truths, which are of universal application to human beings, furnish a Physiological Guide, showing the true laws of sex, in relation to human progress. We find that the laws of physiology point in one practical direction--viz., to the family--as the only institution which secures their observance; they show the necessity of the self-control of chastity in the young man and the young woman, as the only way to secure the strong mental and physical qualities requisite in the parental relation, whilst they also prove the special influence exerted by mutual love in the great work of Maternity. The preparation, therefore, of youth for family life should be the great aim of their sexual education. Experience as well as Reason confirms the direct and indirect teaching of Physiology; they both point to the natural family group as the element out of which a healthy society grows. It is only in the family that the necessary conditions for this growth exist. The healthy and constantly varying development of children naturally constitutes the warmest interest of parents. Brothers and sisters are invaluable educators of one another; they are unique associates, creating a species of companionship that no other relation can supply. To enjoy this interest, to create this young companionship, to form this healthy germ of society, marriage must be unitary and permanent. A constantly deepening satisfaction should exist, arising from the steady growth together through life, from the identity of interest and from the strength of habit. Still farther we learn that such union should take place in the early period of complete adult life. Children should be the product of the first fresh vigour of parents. Everything that exhausts force or defers its freshest exercise is injurious to the Race. Customs of society or incorrect opinions which obstruct the union of men and women in their early vigour, which impair the happiness of either partner, or prevent the strong and steady growth of their union, impair their efficacy as parents, and are fatal to the highest welfare of our Race. CHAPTER II _Social Results of Neglecting these Physiological Laws_