From Henri Cartier-Bresson: The Decisive Moment (1952) in Goldberg 1981: Photography in Print:
“We work in unison with movement as though it were a presentiment of the way in which life itself unfolds. But inside movement there is one moment at which the elements in motion are in balance. Photography must seize upon this moment and hold immobile the equilibrium of it.
The photographer’s eye is perpetually evaluating. A photographer can bring coincidence of line simply by moving his head a fraction of a millimeter. He can modify perspectives by a slight bending of the knees. By placing the camera closer to or farther from the subject, he draws a detail — and it can be subordinated, or he can be tyrannized by it. […]
Sometimes it happens that you stall, delay, wait for something to happen. Sometimes you have the feeling that here are all the makings of a picture — except for just one thing that seems to be missing. But what one thing? Perhaps someone suddenly walks into your range of view. You follow his progress through the view-finder. You wait and wait, and then finally you press the button — and you depart with the feeling (though you don’t know why) that you’ve really got something. Later, to substantiate this, you can take a print of this picture, trace on it the geometric figures which come up under analysis, and you’ll observe that, if the shutter was released at the decisive moment, you have instinctively fixed a geometric pattern without which the photograph would have been both formless and lifeless.
Composition must be one of our constant preoccupations…” (p. 385)