The father of modern philosophy

From Descartes: The Life and Times of a Genius by A.C. Grayling

Part of the contribution made by Descartes’ Discourse was to restore human reason to a status which allowed it to address questions until then regarded by religious orthodoxy as dangerous. In this respect Descartes is to the modern world what Thales, the so-called “Father of Philosophy,” was to the ancient world. The comparison is an illuminating one. Thales asked questions about the nature and origins of the world, and formulated answers that relied solely on reason and observation, making no ancient scriptures. He assumed that the world is a place that makes sense, and that the human mind is capable of understanding it. His example unleashed a brilliant epoch of free thought in classical antiquity, which gave birth to the Western tradition.

What Thales achieved for the human mind in ancient times, Descartes contributed to achieving for the human mind at the beginning of the modern age. He is therefore sometimes aptly described as the “Father of Modern Philosophy” to mark the comparison. He played a key role in helping to rescue enquiry about sublunary things from the stifling and long-frozen grip of religious authority. He did it not by rejecting that authority, for by his own testimony he was a devout Catholic all his life, but by separating things of heaven from things of earth, so that scientific reason could investigate the latter without anxieties over orthodoxy. This left the things of heaven untouched and unthreatened – so Descartes thought and hoped – by what scientific enquiry discovered.