D'Alembert said that it would be well if history could be destroyed; and the general tendency was to ignore the social memory and the common heritage of past experiences which mould a human society and make it something very different from a mere collection of individuals.
Belief in Progress, however, took no extravagant form.

It did not beguile d'Holbach or any other of the leading thinkers of the Encyclopaedia epoch into optimistic dreams of the future which might await mankind.

They had a much clearer conception of obstacles than the good Abbe de Saint-Pierre.

Helvetius agrees with d'Holbach that progress will be slow, and Diderot is wavering and sceptical of the question of indefinite social improvement.

[Footnote: De l'esprit, Disc.ii.cc.