in the grate, touching them deftly here and there with the fire-poker
till they signified a sense of his attention by a brighter glow. For
several weeks I had been observing in him a growing habit of delay in
answering even the most trivial of commonplace questions. His air,
however, was that of preoccupation rather than deliberation: one
might have said that he had "something on his mind."

Presently he said:

"What is a 'machine'? The word has been variously defined. Here is
one definition from a popular dictionary: 'Any instrument or
organization by which power is applied and made effective, or a
desired effect produced.' Well, then, is not a man a machine? And
you will admit that he thinks--or thinks he thinks."

"If you do not wish to answer my question," I said, rather testily,
"why not say so?--all that you say is mere evasion. You know well
enough that when I say 'machine' I do not mean a man, but something
that man has made and controls."

"When it does not control him," he said, rising abruptly and looking
out of a window, whence nothing was visible in the blackness of a
stormy night. A moment later he turned about and with a smile said:
"I beg your pardon; I had no thought of evasion. I considered the
dictionary man's unconscious testimony suggestive and worth something
in the discussion. I can give your question a direct answer easily
enough: I do believe that a machine thinks about the work that it is
doing."

That was direct enough, certainly. It was not altogether pleasing,