The original question, 'Can machines think?' I believe to be too meaningless to deserve discussion.
I believe that at the end of the century the use of words and general educated opinion will have altered so much that one will be able to speak of machines thinking without expecting to be contradicted.
I'm afraid that the following syllogism may be used by some in the future. Turing believes machines think Turing lies with men Therefore machines do not think Yours in distress, Alan
A computer would deserve to be called intelligent if it could deceive a human into believing that it was human.