“As yet the machines receive their impressions through the agency of man’s senses:  one travelling machine calls to another in a shrill accent of alarm and the other instantly retires; but it is through the ears of the driver that the voice of the one has acted upon the other.  Had there been no driver, the callee would have been deaf to the caller.  There was a time when it must have seemed highly improbable that machines should learn to make their wants known by sound, even through the ears of man; may we not conceive, then, that a day will come when those ears will be no longer needed, and the hearing will be done by the delicacy of the machine’s own construction?—­when its language shall have been developed from the cry of animals to a speech as intricate as our own?

“It is possible that by that time children will learn the differential calculus—­as they learn now to speak—­from their mothers and nurses, or that they may talk in the hypothetical language, and work rule of three sums, as soon as they are born; but this is not probable; we cannot calculate on any corresponding advance in man’s intellectual or physical powers which shall be a set-off against the far greater development which seems in store for the machines.  Some people may say that man’s moral influence will suffice to rule them; but I cannot think it will ever be safe to repose much trust in the moral sense of any machine.

“Again, might not the glory of the machines consist in their being without this same boasted gift of language?  ‘Silence,’ it has been said by one writer, ’is a virtue which renders us agreeable to our fellow-creatures.’”

CHAPTER XXIV:  THE MACHINES—­continued

“But other questions come upon us.  What is a man’s eye but a machine for the little creature that sits behind in his brain to look through?  A dead eye is nearly as good as a living one for some time after the man is dead.  It is not the eye that cannot see, but the restless one that cannot see through it.  Is it man’s eyes, or is it the big seeing-engine which has revealed to us the existence of worlds beyond worlds into infinity?  What has made man familiar with the scenery of the moon, the spots on the sun, or the geography of the planets?  He is at the mercy of the seeing-engine for these things, and is powerless unless he tack it on to his own identity, and make it part and parcel of himself.  Or, again, is it the eye, or the little see-engine, which has shown us the existence of infinitely minute organisms which swarm unsuspected around us?