"So, these virtuous people are not only weak, but they are an example of humanity’s finest merits."

I believe you meant something different?

I would change it to all people, not just men, cannot be virtuous if they are weak.  

Weakness makes people pick the easy route.  The easy route is almost always the unethical one.  This is part of the warrior ethos, and everyone should be a warrior.  

Warriors do the right thing no matter how difficult or painful it is.