We act based on our experience, on our expectation of what might happen next. It is only when we take action, though, that we finally know the truth of what actually happens.
We believe we’re free to make any decision whatsoever to take any action whatsoever. But every choice and action we make and take, spontaneous or deliberate, is rooted in the sum total of our experience, in what has happened to us in actuality, imagination, or dream to that moment. We then choose to act based on what this gathering of life tells us will be the probable reaction from our world. It’s only then, when we take action, that we discover necessity.
Necessity is absolute truth. Necessity is what in fact happens when we act. This truth is known and can only be known—when we take action into the depth and breadth of our world and brave its reaction. This reaction is the truth of our existence at that precise moment, no matter what we believed the moment before. Necessity is what must and does actually happen, as opposed to probability, which is what we hope or expect to happen.
Robert McKee. Story: Style, Structure, Substance, and the Principles of Screenwriting
‘Until one is committed, there is hesitancy, the chance to draw back, always ineffectiveness. Concerning all acts of initiative there is one elementary truth the ignorance of which kills countless ideas and endless plans: That the moment one definitely commits oneself then providence moves, too. All sorts of things occur to help one that would never have otherwise occurred. A whole stream of events issues from the decision, raising in one’s favor all manner of unforeseen incidents and meetings and material assistance which no man could have dreamed would come his way. Whatever you can do or dream you can, begin it! Boldness has genius, power, and magic in it.’
W.H. Murray (partially quoting Johann Wolfgang von Goethe) The Scottish Himalayan Expedition 1951. Cited in: Get out of Your Mind and into Your Life: The New Acceptance and Commitment Therapy by Steven Hayes and Spencer Smith.