Planck was a revolutionary in a sense because he became a theoretical physicist at a time when theoretical physics was not yet recognized as a discipline in its own right.

Some of the influences that inspired him, was the law of the conservation of energy and the second law of thermodynamics which became the subject of his doctoral dissertation at Munich.

These influences played a pivotal role in his subsequent research that eventually led him to discover the quantum of action, now known as Planck's constant h, in 1900.

Planck's concept of energy quanta conflicted fundamentally with all past physical theory.

He was driven to introduce it strictly by the force of his logic and is considered by some historians as a reluctant revolutionary.

It wasn't until years later via the work of such scientists like Albert Einstein and Niels Bohr, that the far-reaching consequences of Planck's achievement would be validated.

The ultimate validation arrived in 1918 when Planck was awarded the Nobel Prize for Physics.