Rudolf Arnheim
[Writer and psychologist, b. 1904, Berlin, Germany, d. 2007, Ann Arbor, Michigan.]

 The fundamental peculiarity of the photographic medium; the physical objects themselves print their image by means of the optical and chemical action of light. 
 The ambition of instantaneous photography... was that of preserving the spontaneity of action and avoiding any indication that the presence of the picture taker had a modifying influence on what was going on. 
 When the thing observed... is seen as an agglomeration of pieces, the details lose their meaning and the whole becomes unrecognizable. This is often true of snapshots in which no pattern of salient shapes organizes the mass of vague and complex nuances.