I'm curious to find out if what they're trying to isolate is "discipline." I'm not talking about the colloquial definition of discipline but rather exercising the ability to do what's best even if it's not convenient.

I'm talking about the foresight of the intellect over the mind and body. Often times, when we rationalize things or activities just become habits, the mind and body passively agree. I'd argue that's not actually practicing discipline anymore since there's nothing within ourselves (mind & body) to fight.