We can measure Time in one way only—by counting repeated motions.
Apart from the operation of the physical Law of Periodicity we should have no natural measures of Time. If that statement be true it follows that apart from the operation of this law we could not attain to any knowledge of Time.[11:1] Perhaps this latter proposition may not at first be readily granted. Few, probably, would hesitate to admit that in a condition in which our experience was a complete blank we should be unable to acquire any knowledge of Time; but it may not be quite so evident that in a condition in which experience consisted of a multifarious but never repeated succession of impressions the Knowledge of Time would be equally awanting.[12:1] Yet so it is. The operation of the Law of Periodicity is necessary to the measurement of Time. It is by means, and only by means, of periodic pulsative movements that we ever do or can measure Time. Now, apart from some sort of measurement Time would be unknowable. A time which was neither long nor short would be meaningless. The idea of unquantified Time cannot be conceived or apprehended. Time to be known must be measured.
