Courage is a positive force. The absence of fear is a negative force. Fearlessness is a subcomponent of courage and therefore a positive. Because courage can not exist without fear.
To site a personal experience I had a long night out before a day that I really wanted to surf. So I ended up going straight to the beach being that if i went to sleep I would be sleeping for the day. I showed up at dawn to shoulder/overhead short interval stormy but rideable surf. With no fire in my belly I paddled out. Ducking my first wave I immediately perceived the absence of fear. Duck diving in shallow sand I frequently worrie about the wave splashing off the bottom and forcing the board out of my grip and into my face. But now I did not have the energy to care. And I pushed through the outside easily. Similarily on my first wave, too exhausted to think I took off and flew down the stormy overhead face backside like it was a glassy 3ft. roller and finished by just letting the wall knock me off the board without bothering to turn towards or away from the oncoming close. It was like fallling into a waterbed. I did not know or care where my board was in the foam and getting to the surface was not even a thought in my mind, things were just happening.
That was a very short session, for obvious reasons I could not sustain a long surf. Thinking about that session I can see that utilizing negative energy, a lack of or even denial of fear can open some doors. However I also notice that without courage, without positive energy one can flow but not actualize. In that state I could not have done anything but what I did. So without using exhaustion as a strategy I realize that positive force tempered with negative can generate energy and flow. To make this work sometimes one has to set aside logic and move on straight intuition but as I apply this emotional discipline to my surfing it seems to yield results.