“The world consists of things, which obey rules.”
“Physicalism holds that all that really exists are physical things. Our notion of what constitutes a “physical thing” can change as our understanding of physics improves; these days our best conception of what really exists is a set of interacting quantum fields described by a wave function. What doesn’t exist, in this doctrine, is anything strictly outside the physical realm — no spirits, deities, or souls independent of bodies. It is often convenient to describe the world in other than purely physical terms, but that is a matter of practical usefulness rather than fundamental necessity.”
“This teleological, goal-driven, view of the world is reasonable on its face, but unsupported by science. When Avicenna and Galileo and others suggested that motion does not require a continuous impulse — that objects left to themselves simply keep moving without any outside help — they began the arduous process of undermining the teleological worldview. At a basic level, all any object ever does is obey rules — the laws of physics. These rules take a definite form: given the state of the object and its environment now, we can predict its state in the future. (Quantum mechanics introduces a stochastic component to the prediction, but the underlying idea remains the same.) The “reason” something happens is because it was the inevitable outcome of the state of the universe at an earlier time.”