"Since the inferior always outnumber the superior, the former would always increase more rapidly if they possessed the same capacities for survival and for the procreation of their kind; and the final consequence would be that the best in quality would be forced to recede into the background. Therefore a corrective measure in favour of the better quality must intervene. Nature supplies this by establishing rigorous conditions of life to which the weaker will have to submit and will thereby be numerically restricted; but even that portion which survives cannot indiscriminately multiply, for here a new and rigorous selection takes place, according to strength and health."