For the gradual revolutions are too slow to be discernible in the short period known to us by history and tradition.
Physically and in mental powers men have been pretty much the same in all known ages.

The sciences and arts have flourished now and have again decayed, but when they reached the highest perfection among one people, the neighbouring peoples were perhaps wholly unacquainted with them.

We are therefore uncertain whether at present man is advancing to his point of perfection or declining from it.

[Footnote: Essay on the Populousness of Ancient Nations, ad init.

] The argument is somewhat surprising in an eighteenth century thinker like Hume, but it did not prevent him from recognising the superiority of modern to ancient civilisation.