Psionics

For my own usage, it's a balance between the two factors - discipline/control, and emotional energy.

Psionics requires extreme concentration/mental discipline, in order to function. If you aren't controlled, your efforts will be scattershot, ineffective. To properly move the stone, or perceive another's thoughts, you have to be in control.

However, at the same time... to get real power behind it, emotion is crucial. The phrase Xavier used in First Class is right at the core of my philosophy.

'The balance between rage and serenity.'