“In short, all suicides of the insane are either devoid of any motive or determined by purely imaginary motives. Now, many voluntary deaths fall into neither category; the majority have motives, and motives not unfounded in reality. Not every suicide can therefore be considered insane, without doing violence to language.”

The Mysterious Affair at Styles (1920)

unsourced

The Trouble With Being Born (1973)

Source: City of Ashes

In response on the motives of suicide bombers in a speech at Harvard University http://www.washingtonpost.com/wp-dyn/content/article/2006/09/11/AR2006091100315.html 11 September 2006)
Attributed

"Originals Graphics Multiples" (1973) <!-- as quoted in Man Ray : American Artist (1988) by Neil Baldwin, p. 323 -->
Context: An original is a creation motivated by desire.
Any reproduction of an original is motivated by necessity.
The original is the result of an automatic process, the reproduction, of a mechanical process. In other words: Inspiration then information; each validates the other.
All other considerations are beyond the scope of these statements.
It is marvelous that we are the only species that creates gratuitous forms. To create is divine, to reproduce is human.

Introduction
Motivation and Agency (2003)

Source: The Black Company (1984), Chapter 4, “Whisper” (p. 115)