PROFESSOR WHEWELL, ON CAUSE AND EFFECT. 329 



pendulum, the corrosion, as an aggregate effect, occupies time; and 

 the rates before and after the change are separated by this time. But 

 the application of the drop is the cause; and thus, in this case the final 

 effect is subsequent to the cause, though here, as in the case of me- 

 chanism, the instantaneous forces always produce a simultaneous effect. 



Thus we have in every case a uniform state, or a state which is 

 considered as \xniform, or at least normal; and which is taken as the 

 indication and measure of time; and we have also change, which is con- 

 templated as a deviation from uniformity, and is taken as the indication 

 and measure of cause. The uniform state may be one which never 

 exists, being purely imaginary ; as the case in which no forces act ; and 

 the case in which animal functions go on permanently, the animal neither 

 growing nor wasting. The normal state may also be a state in which 

 change is constantly taking place, as, in fact, even a state of motion is 

 a state of change; such states also are, in a further sense, that of a 

 clock going by starts, and that of an animal constantly growing : in 

 these cases the changes are all merged in a wider view of uni- 

 formity, so that these are taken as the normal states. And in all these 

 cases, successive changes which take place are separated by intervals of 

 time, measured by the normal progress ; and each change is produced by 

 some simultaneous instantaneous cause. But taking the cause in a larger 

 sense, we group these instantaneous causes, and perhaps omit in our 

 contemplation some of the intervening intervals ; and thus assign the 

 cause to a preceding, and the effect to a succeeding time. 



I may observe further, as a corollary from what has been said, that 

 the measure of time is different, when we consider different kinds of 

 causation ; and in each case, is homogeneous with the changes which 

 causation effects. In the consideration of mechanical causes, we measure 

 time by mechanical changes; — by uniform motion, or uniform succession 

 of cycles of motion ; by the rotation of a wheel, or the oscillation of 

 a pendulum. But if we have to consider physiological changes, the 

 progress of time is physiologically measured; — by the normal progress 

 of vital operations ; by the circulation, digestion or developement of the 

 organized body; by the pulse, or by the growth. These different measures 

 of time give to time, so far as it is exhibited by facts and events, 



