God is a challenge because there is no proof of his existence and therefore the search must continue.

It is much more rewarding to do more with less.

AI has by now succeeded in doing essentially everything that requires 'thinking' but has failed to do most of what people and animals do 'without thinking'-that, somehow, is much harder.

We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil.

Meta-design is much more difficult than design; it's easier to draw something than to explain how to draw it.

... the designer of a new system must not only be the implementor and the first large-scale user; the designer should also write the first user manual. ... If I had not participated fully in all these activities, literally hundreds of improvements would never have been made, because I would never have thought of them or perceived why they were important.

In fact what I would like to see is thousands of computer scientists let loose to do whatever they want. That's what really advances the field.