《人口論（英文版）》：

　　The advocate for the present order of things is apt to treat the sect of speculative philosophers either as a set of artful and designing knaves, who preach up ardent benevolence and draw captivating pictures of a happier state of society, only the better to enable them to destroy the present establishments and to forward their own deep-laid schemes of ambition; or as wild and mad-headed enthusiasts,whose silly speculations and absurd paradoxes are not worthy the attention of any reasonable man.

　　The advocate for the perfectibility of man, and of society, retorts on the defender of establishments a more than equal contempt. He brands him as the slave of the most miserable and narrow prejudices, or as the defender of the abuses of civil society, only because he profits by them. He paints him either as a character who prostitutes his understanding to his interest; or as one whose powers of mind are not of a size to grasp any thing great and noble, who cannot see above five yards before him, and who must therefore be utterly unable to take in the views of the enlightened benefactor of mankind.

　　In this unamicable contest the cause of truth cannot but suffer. The really good arguments on each side of the question are not allowed to have their proper weight. Each pursues his own theory, little solicitous to correct or improve it by an attention to what is advanced by his opponents.

　　The friend of the present order of things condemns all political speculations in the gross. He will not even condescend to examine the grounds from which the perfectibility of society is inferred. Much less will he give himself the trouble in a fair and candid manner to attempt an exposition of their fallacy.

　　The speculative philosopher equally offends against the cause of truth. With eyes fixed on a happier state of society, the blessings of which he paints in the most captivating colours, he allows himself to indulge in the most bitter invectives against every present establishment, without applying his talents to consider the best and safest means of removing abuses, and without seeming to be aware of the tremendous obstacles that threaten, even in theory, to oppose the progress of man towards perfection.

　　It is an acknowledged truth in philosophy that a just theory will always be confirmed by experiment. Yet so much friction, and so many minute circumstances occur in practice, which it is next to impossible for the most enlarged and penetrating mind to foresee, that on few subjects can any theory be pronounced just,that has not stood the test of experience. But an untried theory cannot fairly be advanced as probable, much less as just, till all the arguments against it have been maturely weighed, and clearly and consistently refuted.

　　I have read some o'f the speculations on the perfectibility of man and of society with great pleasure. I have been warmed and delighted with the enchanting picture which they hold forth. I ardently wish for such happy improvements. But I see great and, to my understanding, unconquerable difficulties in the way to them. These difficulties it is my present purpose to state; declaring, at the same time, that so far from exulting in them as a cause of triumph over the friends of innovation,nothing would give me greater pleasure than to see them completely removed.

　　The most important argument that I shall adduce is certainly not new. The principles on which it depends have been explained in part by Hume, and more

　　at large by Dr. Adam Smith. It has been advanced and applied to the present subject, though not with its proper weight, or in the most forcible point of view,by Mr. Wallace, and it may probably have been stated by many writers that I have never met with. I should certainly therefore not think of advancing it again,though I mean to place it in a point of view in some degree different from any that I have hitherto seen, if it had ever been fairly and satisfactorily answered.

　　The cause of this neglect on the part of the advocates for the perfectibility of mankind is not easily accounted for. I cannot doubt the talents of such men as God-win and Condorcet. I am unwilling to doubt their candour. To my understanding,and probably to that of most others, the difficulty appears insurmountable. Yet these men of acknowledged ability and penetration scarcely deign to notice it, and hold on their course in such speculations, with unabated ardour and undiminished confidence. I have certainly no right to say that they purposely shut their eyes to such arguments. I ought rather to doubt the validity of them, when neglected by such men, however forcibly their truth may strike my own mind. Yet in this respect it must be acknowledged that we are all of us too prone to err. If I saw a glass of wine repeatedly presented to a man, and he took no notice of it, I should be apt to think that he was blind or uncivil. A juster philosophy might teach me rather to think that my eyes deceived me, and that the offer was not really what I conceived it to be.

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