"To take a concrete instance of the embarrassment which Free Birth would bring, and of the invidious distinctions that would have to be made: which is the better lot?--to be the third daughter of a nineteenth-century, healthy, ugly, penniless, clever, middle-aged, moral, free-thinking German Baron by a beautiful, rich, stupid, plebeian Spanish dancer, with one child by a previous marriage, and a tendency to consumption; or the second son of a twentieth-century American Duke, unhealthy, uncultured, handsome, chaste, Ritualist, elderly and poor, by an English heiress, ugly, low-born, Low Church, ill-bred, intellectual, with a silly and only semi-detached mother? But this would be a problem of unreal simplicity, bearing as much relation to actuality as the first law of motion to the flight of a bird, for your choice would lie not between one pair and another, but among all possible pairs." "All existing pairs possible to you," corrected Marindin. "People manage to choose husbands and wives, though according to your computation the whole of the opposite sex would have to be examined and selected from. In practice the choice is narrowed down to a few individuals. So with the choice of parents--most are already snapped up, monopolised or mortgaged, or contracted for, and you have either to choose from the leavings or postpone your birth, and bide your time a century or two. But the problem is greatly simplified by the P. C." "What is the P. C.?" I murmured. "The Parental Certificate, of course. Throughout the terrestrial branch of our sect no one is eligible for parentage who does not possess it. It is given only to those who have passed the P. D. or Parents' Degree examination, and supplements the old P. L. or Parents' Licence, which was openly bought and sold." "And the qualifications?" "Oh, very elementary. The candidate is required to pass an exam, (both written and oral) in the training of the young, and to be certified of sound mind in sound body. The P. L. itself has been transformed into a licence to keep one, two or more children, according to means." "You see our 'Guide' deals merely with the great typical pairs," explained the publisher. "What Aristotle did for Logic our author has done for Birth. He only pretends to give general categories. Aristotle could not guarantee a man shall properly reason, nor can any individual be infallibly inspired to the wisest choice of parentage. Of course the photographs of parents are of great service to the unborn who are thinking of settling down." "How do they get to see them?" "Oh, as soon as a couple passes the P. D. and receives the P. C. they appear in the illustrated papers--especially the ladies' papers. 'Graduates of the Week' is the heading. And then there is the P. T.--the Pathological Tree." I looked at the publisher in perplexity.