[Hartree describes a calculation a machine might fail to do if programmed naively, and then says:] A human [operator], faced with this unforseen situation, would have exercised intelligence, almost automatically and unconsciously, and made the small extrapolation of the operating instructions required to deal with it. The machine without operating instructions for dealing with negative values of z, could not make this extrapolation...
The moral of this experience is that in programming a problem for the machine, it is necessary to try to take a “machine’s-eye view” of the operating instructions, that is to look at them from the point of view of the machine which can only follow them literally, without introducing anything not explicitly by them, and try to forsee all the unexpected things that might occur in the course of the calculation, and to provide the machine with the means of identifying each one and with appropriate operating instructions in each case. And this is not so easy as it sounds; it is quite difficult to put oneself in the position of doing without any of the things which intelligence and experience would suggest to a human [operator] in such situations.
A passage from Hartree (1949) that could have been quoted in the opening of Complex Value Systems are Required to Realized Valuable Futures: