To me, the difference between reacting and acting, is the consciousness.
When I'm reacting to something, I'm generally doing it without thinking. It can be in conversation, while walking the dogs, out running, etc. My reaction is what my body & mind know to do based on history.
When I am acting, even in basic conversations, I am more conscious about what I contribute. I speak based on what is happening now, versus saying my usual response.
From this place of acting, so much more is possible because I'm not limited by my past experiences; I am open to what the present moment brings.
Can you or have you seen greater possibility when deciding to act instead of react?
The other quote I am reminded of when reading this one, is "jump and your wings will appear," which I love as well. I believe, as well as millions around the world, that you don't need to know the answer or the how, before you do the things. Some call it a god, some call it universal intelligence. Part of me aligns with those, but part of me also believes that it could just be our big beautiful brains. They are so complex & take in so much information that we don't even use on a regular basis; I think it's possible that the answer is just buried deep in there, waiting for an external trigger(person, sign post, article) to bring it to the surface.
Do you think that's absurd? Do you try to have all the answers before doing something? Or, do you trust that you will figure it out "on your way down" so to speak?