How René Descartes might approach Physics

The understanding of the natural world, which some call "physics," has long been obscured by reliance upon the fickle testimony of the senses and the confused notions inherited from scholastic traditions. To establish a truly certain science of bodies, one must first, as I have always insisted, sweep away all such shaky foundations. I will doubt everything that can possibly be doubted concerning the external world, for the senses have often deceived me, and even waking experience can be indistinguishable from a vivid dream.

But just as I discovered my own indubitable existence as a thinking thing, so too can we arrive at a clear and distinct understanding of corporeal substance. What is a body, truly? Not a mere bundle of sensible qualities—color, sound, taste—for these are but modifications of our own minds, not inherent properties of the object itself. Rather, by the natural light of reason, I perceive that the essence of body consists solely in extension: in length, breadth, and depth. It is that which is divisible and mobile, possessing figure and magnitude.

From this simple, geometrically understood essence, the true laws governing the interactions of bodies must be deductively derived. We do not discover these fundamental truths through haphazard experimentation, which can only show us what *is*, but through clear and distinct intellectual apprehension of what *must be*. Considering the immutable nature of God, the perfect and omnipotent creator, we can deduce the most general and simple principles of motion, which He instilled at creation and maintains perpetually. All phenomena, from the motion of planets to the workings of the simplest machine, are but variations of these mechanical interactions, explicable through mathematical reasoning. Thus, by grounding…

Imagined perspective — an AI synthesis grounded in René Descartes’s recorded ideas and methods, not a quotation or a statement they actually made.