Philosophy is different from science and from mathematics. Unlike science it doesn't rely on experiments or observation, but only on thought. And unlike mathematics it has no formal methods of proof. It is done just by asking questions, arguing, trying out ideas and thinking of possible arguments against them, and wondering how our concepts really work.
If you think about it, the inside of your own mind is the only thing you can be sure of.
The most radical conclusion to draw from this would be that your mind is the only thing that exists. This view is called solipsism. It is a very lonely view, and not too many people have held it.
[T]here is also a philosophical question about the relation between mind and brain, and it is this: Is your mind something different from your brain, though connected to it, or is it your brain? Are your thoughts, feelings, perceptions, sensations, and wishes things that happen in addition to all the physical processes in your brain, or are they themselves some of those physical processes?
Physicalists believe that nothing exists but the physical world that can be studied by science: the world of objective reality. But then they have to find room somehow for feelings, desires, thoughts, and experiences -- for you and me -in such a world.
Words are mostly used in talking and writing, rather than just as labels.
Definitions can't be the basis of meaning for all words, or we'd go forever in a circle. Eventually we must get to some words which have meaning directly.
This is an idea of "can" or "could have" which we apply only to people (and maybe some animals). When we say, "The car could have climbed to the top of the hill," we mean the car had enough power to reach the top of the hill if someone drove it there. […] But when it comes to people, we seem to think that they can do various things they don't actually do, just like that,without anything else happening differently first. What does this mean?
This is a funny question: we all know what it means to dosomething. But the problem is, if the act wasn't determined in advance, by your desires, beliefs, and personality, among other things, it seems to be something that just happened, without any explanation. And in that case, how was it your doing?
The ideas of wrong and right are different from the ideas of what is and is not against the rules. Otherwise they couldn't be used in the evaluation of rules as well as of actions.
There are many philosophical problems about the content of morality -- how a moral concern or respect for others should express itself; whether we should help them get what they want or mainly refrain from harming and hindering them; how impartial we should be, and in what ways. I have left most of these questions aside because my concern here is with the foundation of morality in general -- how universal and objective it is.