Darwin expresses his dismay and discouragement because, in comparison to how very scrupulous a man is about the pedigree of his livestock, when it comes to his own marriage, “…he rarely, or never, takes any such care. He is impelled by nearly the same motives as the lower animals, when they are left to their own free choice…” ((Charles Darwin, Descent of Man and Selection in Relation to Sex, (originally published 1871: reprint with introduction published New York: Barnes & Noble, 2004), 556.)) Of course, marriage in Jewish and Christian traditions is an exalted spiritual covenant between the two and God. With regard to how the “inferiors” should approach marriage, he says, “Both sexes ought to refrain from marriage if they are in any marked degree inferior in body or mind; but such hopes are Utopian, and will never be even partially realized until the laws of inheritance are thoroughly known. Everyone does good service who aids toward this end. When the principles of breeding and inheritance are better understood, we shall not hear ignorant members of our legislature rejecting with scorn a plan for ascertaining whether or not consanguineous marriages are injurious to man.” ((Darwin, Descent, 556.))
Not only is physical or mental deficiency reason to not marry, but he also said, “All ought to refrain from marriage who cannot avoid abject poverty for their children, for poverty is not only a great evil, but tends to its own increase by leading to recklessness in marriage. On the other hand, as Mr. Galton has remarked, if the prudent avoid marriage, while the reckless marry, the inferior members tend to supplant the better members of society.” ((Darwin, Descent, 556,557.)) In absolute contradistinction, the Bible and many other religions, assign no evil to poverty. Oh well, the Darwinian Decalogue says, Thou shalt not marry if you are physically or mentally weak and/or unable to provide…enough Darwin dollars.