Liebnitz's involvement with the Harz Mountain mining project ultimately proved to be a fiasco. In his optimism, he had not forseen the natural hostility of the expert mining engineers towards a novice proposing to teach them their trade. Nor had he allowed for the inevitable break-in period a novel piece of machinery requires or for the unreliability of the winds.
Unlike the usual experience with a new untried gadget, Turing's Bombes, built from his design, worked correctly as soon as they were made.
"There are several theorems which say almost exactly that ... if a machine is expected to be infallible, it cannot also be intelligent... But these theorems say nothing about how much intelligence may be displayed if a machine makes no pretence at infallibility." [Turing]
There is nothing in Godel's theorem to preclude the mathematical powers of a human mind being equivalent to an algorithmic process that produces false as well as true statements.
It is interesting to contrast von Neumann's view of computer programming as an activity with Turing's; von Neumann called it "coding" and made it clear that he thought of it as a clerical task requiring little intellect. A revealing anecdote tells of a practice at the Institute for Advanced Study computer facility of using students to translate by hand, computer instructions written using human-readable mnemonics into machine language. A young hot-shot programmer proposed to write an assembler that would do this conversion automatically. Von Neumann is said to have responded angrily that it would be wasteful to use a valuable scientific tool to do a mere clerical job. In his ACE report, Turing said that the process of computer programming "should be very fascinating. There need be no real danger of it ever becoming a drudge, for any processes that are quite mechanical may be turned over to the machine itself."
There is no reason to think that a full scale ACE-style computer would not have worked well if the organization and resources to build one had been there. The issue is best understood in the more general context of the question of which computer functions should be supplied by the hardware and which by software. Turing had proposed a relatively simple machine in which a lot was left to be supplied by software, but where, in compensation, the programmer had very substantial control of underlying machine operations.
"I expect that digital computing machines will eventually stimulate a considerable interest in symbolic logic... The language in which on communicates with these machines ... forms a sort of symbolic logic." [Turing]
Searle tells us that Deep Blue "has a bunch of meaningless symbols." Well, if you could look inside Deep Blue when it was in operation, you wouldn't see any symbols, meaningful or not. At the level of circuits, electrons are moving around. Just as, if you look inside Kasparov's skull while he is playing, you wouldn't see any chess pieces, you'd see neurons firing.
Our consciousness is a principal way in which each of us experiences his or her unique individuality. But we know it only from the inside. We experience our own consciousness but not that of anyone else.