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 Godwin 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.

In entering upon the argument I must premise that I put out of the
question, at present, all mere conjectures, that is, all suppositions,
the probable realization of which cannot be inferred upon any just
philosophical grounds. A writer may tell me that he thinks man will
ultimately become an ostrich. I cannot properly contradict him. But
before he can expect to bring any reasonable person over to his
opinion, he ought to shew that the necks of mankind have been gradually
elongating, that the lips have grown harder and more prominent, that
the legs and feet are daily altering their shape, and that the hair is
beginning to change into stubs of feathers. And till the probability of
so wonderful a conversion can be shewn, it is surely lost time and lost
eloquence to expatiate on the happiness of man in such a state; to
describe his powers, both of running and flying, to pai