Thanks Alexander, your arguments do definitely convince me of a persisting substance during change. With regards to it being an argument for prime matter, your right that it is a bit doubtful, but I looked at a preview of Dr. Oderberg's Real essentialism where he states that quarks or other fundamental particles cannot be the fundamental substance that persist through change as they themselves substantially change and there is no metaphysical guarantee that they would stay the same during substantial change. Do you find this argument convincing for the existence of prime matter and if yes/no why/why not as for me the last part of the no metaphysical guarantee is still somewhat unclear to me.