Taken from a scholastic disputation from my Natural Science course:
Thesis: “Motion (i.e., change) is impossible”
The Parmenidean Argument:
Major: Motion is a passage from being to non-being and vice-versa.
Minor: But non-being is impossible.
Conclusion: Therefore, motion is impossible.
In support of the premises:
Major: This is posited as the definition of motion.
Minor: Non-being cannot exist, by definition. Therefore, the passage to or from non-being is impossible.
The Aristotelian-Scholastic Reply:
I distinguish the major: that motion is a passage from being secundum quid to non-being secundum quid and vice-versa, I concede; but that motion is a passage from being simpliciter to non-being simpliciter and vice-versa, I deny. Explanation: Motion is a passage from potential being to actual being. Something in potency is being simpliciter and non-being secundum quid: that it to say, something that is in potency is in the fundamental sense of having existence, but it is not in a secondary respect, insofar as it is not yet this or that, it is not such and such. When this thing that is in potency is moved to act, it receives a new modification that it lacked before (or loses what it had before), all the while remaining in existence. Motion does not involve the existence of non-existence, but the modification of what is in existence throughout the motion. This is true not only of accidental change, but also, in its own way, of substantial change (absolute generation and corruption).
I contradistinguish the minor: that the existence of non-being simpliciter is impossible, I concede; but that the existence of non-being secundum quid is impossible, I deny. Explanation: It is certainly impossible for a substance both to exist and not to exist at the same time--this is the primary meaning of the principle of non-contradiction. But it is not impossible for a substance or subject (e.g., matter) to lack a certain form, and hence to be non-being in a certain respect; the latter is a being simpliciter, but is non-being secundum quid, i.e., insofar as it is (exists), but is not such and such.
And I deny the conclusion.