It was only towards the close of the period--which is commonly known as the age of "Illumination"-- that Progress came to the front, and it is interesting to observe the reason.
Wolf was the leading successor and interpreter of Leibnitz.

He constrained that thinker's ideas into a compact logical system which swayed Germany till Kant swept it away.

In such cases it usually happens that some striking doctrines and tendencies of the master are accentuated and enforced, while others are suffered to drop out of sight.
So it was here.

In the Wolfian system, Leibnitz's conception of development was suffered to drop out of sight, and the dynamic element which animated his speculation disappeared.

In particular, he had laid down that the sum of motive forces in the physical world is constant.
His disciples proceeded to the inference that the sum of morality in the ethical world is constant.