This sweet strain had been enchanting the public for four or five years, when Malthus ventured to interrupt it with his modest anonymous _Essay on the Principle of Population as it affects the Future Improvement of Society_. The writer claims to be as hearty a philanthropist as Mr. Godwin, but he cannot allow the wish to be father to the thought, and believe in future perfection against evidence. To prove a theory true, he says, it is not enough to show that you cannot prove its contradiction, or that you can prove its usefulness. It would be very useful to have eyes in both sides of our head; but that does not prove that we are going to have them. If you told me that man was becoming a winged creature like the ostrich, I should not doubt that he would find wings very useful, but I could hardly believe your prophecy without some kind of proof beyond the mere praises of flying. I should ask you to show palpable signs in his body and habits that such a change was going on, that his neck has been lengthening, his lips hardening, and his hair becoming feathery. In the same way, when you tell me that man is becoming a purely intellectual being, content with plain living and high thinking, I see there might be advantage in the change, but I ask for signs that it is in progress. I see none; but, on the contrary, I see strong reasons for believing in its impossibility. Grant me two postulates, and I disprove your millennium. The first is, that food is necessary; the second, that the instinct for marriage is permanent. No one denies the first, and Godwin’s denial of the second is purely dogmatic. He has given us no proofs. Men have no doubt made progress in other respects; they have passed from barbarism to civilization. But in respect of the second postulate they are the same now as they were 4000 years ago. Individual exceptions are individual exceptions still. I am bound, therefore, to believe in the truth of my postulates, and I infer from them the impossibility of your millennium.