Does the artist rigidly control the outcome of their work via their will and intention, does the painting itself dictate, and where is the balance here?

I have been musing this time-worn and eternally intriguing debate when recently working en-plein-air in watercolour; apart from the artist, the painting, and the watery paint, there was weather and the light to consult as well.

The Artist calling the shots - When I wanted to achieve a 'finished painting', i was fighting the weather (rushing to get out of the cold) and I was having a race with the light (sun going down). I got an intense and frantic image.

Letting the work unfold and nature have its say: When I was concentrating on the process and quietly letting the water flow, then the sun went down as I worked and so caused me to stop. I got a calm strong image with gaps.