Turgot, and Voltaire in his way, had traced the growth of civilisation; the originality of Chastellux lay in concentrating attention on the eudaemonic issue, in examining each historical period for the purpose of discovering whether people on the whole were happy and enviable.

Has there ever been a time, he inquired, in which public felicity was greater than in our own, in which it would have been desirable to remain for ever, and to which it would now be desirable to return?
He begins by brushing away the hypothesis of an Arcadia.

We know really nothing about primitive man, there is not sufficient evidence to authorise conjectures.

We know man only as he has existed in organised societies, and if we are to condemn modern civilisation and its prospects, we must find our term of comparison not in an imaginary golden age but in a known historical epoch.

And we must be careful not to fall into the mistakes of confusing public prosperity with general happiness, and of considering only the duration or aggrandisement of empires and ignoring the lot of the common people.
His survey of history is summary and superficial enough.