Herbert Spencer On Motion And Rest

Herbert Spencer, First Principles (1911; Williams & Norgate, London), 43.

‘Once more there is the old puzzle concerning the connexion between Motion and Rest.

A body travelling at a given velocity cannot be brought to a state of rest, or no velocity, without passing through all intermediate velocities.

It is quite possible to think of its motion as diminishing insensibly until it becomes infinitesimal; and many will think equally possible to pass in thought from infinitesimal motion to no motion.

But this is an error.

Mentally follow out the decreasing velocity as long as you please, and there still remains some velocity; and the smallest movement is separated by an impassable gap from no movement. As something, however minute, is infinitely great in comparison with nothing; so is even the least conceivable motion infinite as compared with rest.’

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