The foregoing is the case of an action in conformity with the ideal, but quite contrary to human nature as it is at present. A similar contradiction appears in reproduction. Man came from animals amongst which unlimited reproduction was an important factor in the preservation of the species, as it allowed the species to survive under all sorts of bad conditions, such as diseases, combats, attacks of enemies, and changes of climate. Although man, according to the laws of human nature, is capable of reproducing extremely rapidly, the ideal of his happiness makes a restriction of this power necessary. Thus orthobiosis, based upon knowledge of human nature, would set limits to a function which is perhaps the most natural of all. The restriction which is already partially adopted will come more and more into operation as the struggle against diseases, the prolongation of human life, and the suppression of war make progress. It will be one of the chief means of diminishing the most brutal forms of the struggle for existence, and of increasing moral conduct amongst mankind.
Just as Rimpau began to study the nature of plants before trying to realise his ideal, so also varied and profound knowledge is the first requisite for the ideal of moral conduct. It is necessary not only to know the structure and function of the human organism, but to have exact ideas on human life as it is in society. Scientific knowledge is so indispensable for moral conduct that ignorance must be placed among the most immoral acts. A mother who rears her child in defiance of good hygiene, from want of knowledge, is acting immorally towards her offspring, notwithstanding her feeling of sympathy. And this also is true of a Government which remains in ignorance of the laws which regulate human life and human society.
It must be well understood that I am not here thinking of written knowledge, set down in treatises and volumes. Rimpau and Burbank went outside manuals of botany to obtain their knowledge. Besides books, wide ideas on the practice of life are required to direct aright the conduct of men. A doctor who has just finished his studies at the hospital, notwithstanding all his knowledge, is not yet sufficiently trained to be a good practitioner. He must acquire the habit of treating patients, and for this years are required. So also is it with regard to the practical applications of the principles of morality. The regulation of conduct requires profound knowledge both theoretical and practical, and men selected to frame or to apply laws of morality must have this double qualification. If the human race come to adopt the principles of orthobiosis, a considerable change in the qualities of men of different ages will follow. Old age will be postponed so much that men of from sixty to seventy years of age will retain their vigour, and will not require to ask assistance in the fashion now necessary. On the other hand, young men of twenty-one years of age will no longer be thought mature or ready to fulfil functions so difficult as taking a share in public affairs. The view which I set forth in _The Nature of Man_ regarding the danger which comes from the present interference of young men in political affairs has since then been confirmed in the most striking fashion.