Sexism, Racism, and Other '-ism's: What's Right and What's Right

Discriminatory issues such as sexism and racism get a lot of attention nowadays. Enough so that I shouldn't need to argue whether or why they are bad, or still a problem. Rather, I'd like to make a meta-argument about the issue.

As a note, this argument is general to all issues of difference between people, not just racism, sexism, or even groups - it also applies to individual differences.