Dave,

I'd rather replace von Neumann's automata quotation (third one in 
your list) with the following one, which seems to my view much more 
important from the viewpoint of (a very big part of) 20th century 
mainstream economics (automata are, or will presumably be, a matter 
of 21st century economics):

<<As a mathematical discipline travels far from its empirical source, 
or still more, if it is a second and third generation only indirectly 
inspired by ideas coming from "reality", it is beset with very grave 
dangers. It becomes more and more purely aestheticizing, more and 
more purely l'art pour l'art. This need not be bad if the field is 
surrounded by correlated subjects, which still have closer empirical 
connections, or if the discipline is under the influence of men with 
an exceptionally well-developed taste. But there is a grave danger 
that the subject will develop along the line of least resistance, 
that the stream, so far from its source, will separate into a 
multitude of insignificant branches, and that the discipline will 
become a disorganized mass of details and complexities. In other 
words, at a great distance from its empirical source, or after much 
"abstract" inbreeding, a mathematical subject is in danger of degeneration.>>
(John von Neumann 1961 [1947], "The mathematician", in: Taub A.H. 
(ed.), John von Neumann. Collected works, Oxford: Pergamon Press, 
1961-63, vol. I, p. 9).

Nicola Giocoli