All errors in politics and ethics have sprung, he asserts, from false ideas which are closely connected with errors in physics and ignorance of the laws of nature.

And in the new doctrine of Progress he sees an instrument of enlightenment which is to give "the last blow to the tottering edifice of prejudices." It would not be useful to analyse Condorcet's sketch or dwell on his obsolete errors and the defects of his historical knowledge.

His slight picture of the Middle Ages reflects the familiar view of all the eighteenth century philosophers.

The only contribution to social amelioration which he can discover in a period of nearly a millennium is the abolition of domestic slavery.

And so this period appears as an interruption of the onward march.