Many people, perfectly good-hearted, but somewhat narrow-minded, object strongly to the idea of conjugal prudence, and regard scientific checks to population as “a violation of nature’s laws, and a frustration of nature’s ends.” Such people, a hundred years ago, would have applauded the priest who objected to lightning conductors as being an interference with the bolts of Deity; they exist in every age, the rejoicers over past successes, and the timid disapprovers of new discoveries. Let us analyse the argument. “A violation of nature’s laws;” this objection is couched in somewhat unscientific phrase; nature’s “laws” are but the observed sequences of events; man cannot violate them; he may disregard them, and suffer in consequence; he may observe them, and regulate his conduct so as to be in harmony with them. Man’s prerogative is that by the use of his reason he is able to study nature outside himself, and by observation may so control nature as to make her add to his happiness instead of bringing him misery. To limit the family is no more a violation of nature’s laws than to preserve the sick by medical skill; the restriction of the birth-rate does not violate nature’s laws more than does the restriction of the death-rate. Science strives to diminish the positive checks; science should also discover the best preventive checks. “The frustration of nature’s ends.” Why should we worship nature’s ends? Nature flings lightning at our houses; we frustrate her ends by the lightning conductor. Nature divides us by seas and by rivers; we frustrate her ends by sailing over the seas, and by bridging the rivers. Nature sends typhus fever and ague to slay us; we frustrate her ends by purifying the air, and by draining the marshes. Oh! it is answered, you only do this by using other natural powers. Yes, we answer, and we only teach conjugal prudence by balancing one natural force against 192another. Such study of nature, and such balancing of natural forces, is civilisation.