about phil essay

Having wasted two weeks' time, now I'm getting to my philosophy essay. After tossing around a bit, I finally decided to focus on philosopher Berkeley's ontology.

But what I'm not sure about is whether Berkeley's idealism is right. His theory is an attack on materialism, and holds that all sensible things exist only in human minds - they are not corporeal substances. For example, heat and cold exist only when we feel them. They don't exist without our minds. Do you guys think it true or not? I agree with him, at least in this heat & cold case, because heat and cold are what we feel. I think there exists kind of relativity. For instance, what you feel cold in summer could make you feel warm or hot in winter. Yes, Berkeley did explain it using the relativity argument.

However, as for light and sound, I prefer the materialism theory as what we have learnt in physics in high school. Light is acutally a massive sequence of particles in the air. This is all that I can remember about light. And sound is the motion of air under some frequency (this is my own reflection, if there's any mistake, please help correct).

So don't know if I could split it up - going for the heat & cold argument and against the sound and light ones. But what would the ultimate opinion on Berkeley's ontology be? I think I should have a main topic, and analyze its fissiparous effects later on.

What do you guys think? Please feel free to put forward your opinions. That'd be more than appreciated!