What's All the Fighting About?

I have always been a very passive individual. I loathe physical fighting, even verbal fighting, for that matter. I don't like any physical altercations at all, avoiding any and every fight myself all through grammar school and high school. Here's the conflict. As my son is growing up, I want him to be able to defend himself against bullies and people who threaten to harm him. Yet, I don't want to raise a bully myself. My very loving son is super affectionate and often cries more than his younger sister if he unintentionally hurts her. This is a quality that I find endearing and kind. And I often praise my son for being extremely caring towards others. However, I get the feeling from family and friends that boys should be raised to be tougher, and that I have to be careful not to raise a wimp. By teaching my son to walk away from confrontations, never to hit or say mean things to anyone, am I telling him not to defend or stick up for himself?