How René Descartes might approach Physics

Let us consider this matter of "physics," this study of nature's workings. What foundations may we lay for such a pursuit, so that our conclusions are not built upon shifting sands? My method, as I have begun to demonstrate, demands that we first clear away all that is uncertain. The senses, those deceptive messengers, present us with a world of motion, of color, of sound. But have they not often tricked me? A stick appears bent in water; distant towers seem small. Thus, I can place no absolute trust in these fleeting impressions.

Instead, I must turn inward, to the realm of pure thought. If I doubt all things, if I question the very existence of this physical world, what remains? There remains the doubter himself. For in the act of doubting, I am thinking, and if I am thinking, then I must exist, at least as a thinking thing. *Cogito, ergo sum*. This is my first, indubitable truth.

From this certain point, we may proceed. The ideas of extension, of shape, of motion – these are clear and distinct to my understanding. Even if this perceived world were an illusion, the very concept of extension, of a body occupying space, is something I can grasp with certainty. This extension, this divisibility, this capacity for motion – these are the fundamental attributes of matter. The "physics" of the world, then, must be understood not through the confused perceptions of our senses, but through the clear and distinct ideas of geometry and mechanics, applied to this extended substance. We must reduce the phenomena of nature to their most basic, measurable components, and then, by the natural light of reason, deduce their necessary consequences. Only then can we claim to possess true knowledge of the material world.

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