It was to establish the lines of communication among all departments, "to enclose in the unity of a system the infinitely various branches of knowledge." And it was to be a library of popular instruction.

But it was also intended to be an organ of propaganda.

In the history of the intellectual revolution it is in some ways the successor of the Dictionary of Bayle, which, two generations before, collected the material of war to demolish traditional doctrines.

The Encyclopaedia carried on the campaign against authority and superstition by indirect methods, but it was the work of men who were not sceptics like Bayle, but had ideals, positive purposes, and social hopes.

They were not only confident in reason and in science, but most of them had also a more or less definite belief in the possibility of an advance of humanity towards perfection.
As one of their own band afterwards remarked, they were less occupied in enlarging the bounds of knowledge than in spreading the light and making war on prejudice.