Ethics includes the consideration of what people should do and why. It's not "just" a matter of opinion. Someone is not the Queen of England, just because she thinks she is. We put most people who think that way in mental hospitals. They need some serious help. Of course, the Queen of England also happens to think she's the Queen of England, but it's not her opinion that makes this true. She actually is the Queen of England. There are methods other than determining what one's opinion is by which we are able to determine whose opinion is right and whose is wrong.

When we speak of the actions of human beings that affect other human beings, the criterion is not personal tastes, it's reason. If we disagree about what people should do, we give our reasons, and if we don't, we're asked for them. This does not mean, however, that the only basis for the morality of a human action can be reason. In response to the question, "Why did you do that?" A good reason might be, "Because I care about you." Feelings are sometimes good reasons for doing things. But if you slap me and then claim you did it because you care about me.....well, perhaps you should consider "visiting" some of the Queen Elizabeths from the first paragraph. At the very least, you need some serious help!

So, the next time someone comments that truth or ethics are just "a matter of opinion", remember that matters of opinion are of two types and truth is not, as their statement usually implies, a matter of taste. You might consider a response like this one: "Yes, it's a matter of opinion, but the more important question is whether that opinion is right or wrong!"