The Argument from Motion

"The argument from motion", often referred to as "the argument from change", was proposed by Thomas Aquinas.

Plants flower and seed, and animals feed and breed, all changing with time. A seed contains the potential to become a plant, and 'moves' from being a seed to being a plant. In this context the term 'moves' is used far more broadly than the narrow sense that a car travels from A to B, although that is included. The argument from motion relies on the concepts of potentiality and actuality rather than that of causal sequence.

The argument can be summarised as

Nothing changes itself. The universe is the sum total of all these moving things. If there is nothing outside the material universe, then there is nothing that can cause the universe to change.

This argument assumes causality to be a universal truth, and uses this to assert the need for an Unmoved Mover or an Uncaused Cause to break the resulting infinite regress. There are a number of rebuttals to the argument that show it is inconsistent with modern science and logic, and some are listed below.

(1) Physics is no longer classical. The idea that no movement can happen without something else causing the movement, is not just pre-Einsteinian, it is pre-Newtonian. When people thought that no motion was possible without a mover, they believed that angels had to push the planets to keep them moving.

(2) Two bodies at rest will start to move towards each other due to gravity. They can be each other's first mover. Therefore, the prior mover requirement is unnecessary, in fact, gravity means that a universe without motion is inconceivable and no first mover is needed.

(3) Pairs of virtual particles are created (and annihilated) all of the time, out of literally nothing. These particles affect each other's motion, thus disproving Aquinas's premise. Not all events necessarily have causes. In quantum mechanics, not all events need a cause that proceeds it. To complicate matters, identical experiments can have different outcomes in quantum mechanics. These differences are spontaneous or 'uncaused' and they are mundane patterns of scattering electrons and photons.

(4) Einstein's General Relativity supports closed time loops in which an object can meet itself in the past. These are at odds with the causality assumed in Aquinas' argument.

(5) There is no good reason for allowing the Unmoved Mover to exist without a cause. This is a case of special pleading and there is no good reason to accept it. If nothing moves without a prior mover, then God must need a prior mover, as well. Otherwise God is nothing, which contradicts the conclusion. Thus, either the premise is untrue, in which case the argument is unsound, or the conclusion doesn't follow, in which case the argument is invalid. In fact, as stated, the argument is clearly self-contradictory. Who created God?

(6) If for some reason it is possible to show that there has to be a Unmoved Mover, why would this need to be a being? Why could it not be the universe itself, or some team of super gods that created lesser gods who created lesser gods who created the universe? Why could it not be a random quantum fluctuation? Aside from the fact, that the arbitrary use of god in the argument carries a lot of undesirable cultural baggage, denoting an intelligent being, the decision to insert god as the starting point as the creator of the universe is simply arbitrary and without justification. The argument simply does not demonstrate anything like a god, but just the cultural baggage of the person using the argument.

(7) Imagine there was evidence for the notion of a being that created the universe, there is no reason to believe that this god is the god of any particular religion. Theists simply go from 'I have proved the need for a god' to 'My god is real' without any convincing argument that bridges this huge gap.

(8) Even if there is an infinite regress of causes, so what? The human mind is uncomfortable with the concept of infinity, but reality has no obligation to make humans comfortable. An infinite regress may turn out to be the correct explanation.