I am writing a philosophy essay. For substance dualism?

Just wait until you get old. Then you will see that your body just can no longer keep up with your mind. One grows old and the other does too but just does not realize it. No longer do the dual relation work so well. Not like it was when they first came together in one substance. Now, after many years seems they are not so together as they would like to be. Personally I should have taken better care of them both.

Plato's cave can not be dis-proven, and both atheism(materialism) and Idealism try to use logical positivism to come to an ordered conclusion on the basis of the validity of the sense's which has never been proven. A better person to research about this topic is Rene Descartes and "I think there for I am" which is the only proven with holding factor one can actually say without bringing up the notion of god or the validity of the sense's. I would also research about both Buddhism and Metaphysics/quantum physics Plus "the many worlds theory".

I am writing a philosophy essay. For substance dualism?
I have established there are 2 different substances, physical and mental.

~~~ You cannot 'establish' any such thing!
The only difference between perceiving a 'thought' or a 'rock' is 'magnification/Perspective!
Ultimately, they are both made of the same thing!
Such 'duality' is ignorance, and not understanding this. It is 'duality' in appearance (in the imagination/thoughts) only!