“Computer science research is different from these more traditional disciplines. Philosophically it differs from the physical sciences because it seeks not to discover, explain, or exploit the natural world, but instead to study the properties of machines of human creation. In this it as analogous to mathematics, and indeed the "science" part of computer science is, for the most part mathematical in spirit. But an inevitable aspect of computer science is the creation of computer programs: objects that, though intangible, are subject to commercial exchange.”

Bauer (1971) "Software Engineering." Information Processing: Proceedings of the IFIP Congress 1971, Ljubljana, Yugoslavia, August 23-28, 1971.

Reflections on Software Research (1984)

Dijkstra (1999) "Computing Science: Achievements and Challenges" https://www.cs.utexas.edu/users/EWD/transcriptions/EWD12xx/EWD1284.html (EWD 1284).
1990s

Introduction
Mindstorms: Children, Computers, and Powerful Ideas (1980)

Dijkstra (1986) On a cultural gap http://www.cs.utexas.edu/users/EWD/transcriptions/EWD09xx/EWD924.html (EWD 924).
1980s
Context: A confusion of even longer standing came from the fact that the unprepared included the electronic engineers that were supposed to design, build and maintain the machines. The job was actually beyond the electronic technology of the day, and, as a result, the question of how to get and keep the physical equipment more or less in working condition became in the early days the all-overriding concern. As a result, the topic became – primarily in the USA – prematurely known as ‘computer science’ – which, actually, is like referring to surgery as ‘knife science’ – and it was firmly implanted in people’s minds that computing science is about machines and their peripheral equipment. Quod non [Latin: "Which is not true"]. We now know that electronic technology has no more to contribute to computing than the physical equipment. We now know that programmable computer is no more and no less than an extremely handy device for realizing any conceivable mechanism without changing a single wire, and that the core challenge for computing science is hence a conceptual one, viz., what (abstract) mechanisms we can conceive without getting lost in the complexities of our own making.

Source: "Does the history of psychology have a future?." 1994, p. 472

ACM Queue A Conversation with Alan Kay Vol. 2, No. 9 - Dec/Jan 2004-2005 http://queue.acm.org/detail.cfm?id=1039523
2000s, A Conversation with Alan Kay, 2004–05

1920s, Science and the Modern World (1925)

Source: The Mathematical Tourist: New and Updated Snapshots of Modern Mathematics (1998), Chapter 1, “Explorations” (p. 10)