Notes

enjoys similar empirical support. A puddle’s potential to grow larger is actualized by rain. The cool air actualizes the fresh coffee’s potential to become colder. A forceful flick of the wrist actualizes the flyswatter’s potential to kill the fly.

However, The causal principle of the second premise is not only justified on the basis of empirical evidence but is rationally entailed from what change is. Go back to our example of the acorn, where it is actually a seed, but could potentially become an oak tree. So we say that the acorn or seed is in a state of actuality, in that it currently exists and the oak tree is a potency, in that it does not exist currently but could potentially exist. We then see that it is impossible for something to be actual and potential at the same time because that would entail a contradiction, namely that it currently exists and does not exist. But since a potency, like the potential oak tree, does not exist (yet), it can not do or cause anything including actualize itself and therefore is actualized by an external being that is in the state of actuality like rain and sunlight. Now once a potential is actualized in later events such as when the potential to become an oak tree is actualized, it becomes an existing actuality rather than a non-existing being or property in which case, it would have the ability to cause change and actualize other potentials by virtue of being existent rather than not so that once the acorn does become an oak tree, then the oak tree can actualize other potencies such as the potential to produce oxygen or to feed a starving animal.