“The device [electronic I Ching calculator] also functioned as an ordinary calculator, but only to a limited degree. It could handle any calculation which returned an answer of anything up to 4. …anything above 4 it represented merely as "A Suffusion of Yellow." Dirk was not certain if this was a programming error or an insight beyond his ability to fathom, but he was crazy about it anyway, enough to hand over twenty pounds of ready cash for the thing.”
Source: The Long Dark Tea-Time of the Soul (1988), Ch. 10
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Douglas Adams 317
English writer and humorist 1952–2001Related quotes

“Since then I never pay attention to anything by "experts". I calculate everything myself.”
After having been led astray on neutron-proton coupling by reports of "beta-decay experts".
Part 5: "The World of One Physicist", "The 7 Percent Solution", p. 255
Surely You're Joking, Mr. Feynman! (1985)

Probably a misattribution which instead originated with David Mermin; in "Could Feynman Have Said This?" http://scitation.aip.org/journals/doc/PHTOAD-ft/vol_57/iss_5/10_1.shtml?bypassSSO=1, by N. David Mermin, in Physics Today (May 2004), p. 10, he notes that in an earlier Physics Today (April 1989), p. 9, he had written what appears to be the earliest occurrence of the phrase:
If I were forced to sum up in one sentence what the Copenhagen interpretation says to me, it would be "Shut up and calculate!"
Disputed and/or attributed
5. The Rules of Probability. p. 78.
Understanding Uncertainty (2006)
“Rational actors are significantly constrained by limitations of information and calculation.”
Source: A behavioral theory of the firm, 1959, p. 214
R. H. Dalitz, Another side to Paul Dirac, in Paul Adrien Maurice Dirac (Cambridge University, Cambridge, 1987) Chapter 10.

Major Pierre Ducos, p. 233
Sharpe (Novel Series), Sharpe's Honor (1985)

Le propre d’un grand homme est de dérouter les calculs ordinaires. Il est sublime et attendrissant, naïf et gigantesque.
Part I, ch. XV.
Letters of Two Brides (1841-1842)