292 THE FOUNDATIONS OF ZOOLOGY 



actively employed by a user; but a clock wound up and started is 

 different from a clock run down, and so long as its pendulum swings 

 it counts the passing seconds and tells the flight of time whether we 

 use it or not. Once set agoing, it is independent of a user, and it 

 does its work "by itself" until it comes to rest; although its inde- 

 pendence of a user does not imply that it is useless, for so long as 

 it runs any one may use it who knows how. If it were kept wound 

 up by a wheel under a waterfall, it would be part of the mechanism 

 of nature; and, once started, it would, barring accidents, be inde- 

 pendent of human users. When the mechanism of nature is com- 

 pared to human machines, these often seem to be thought of in this 

 way, as contrasted with instruments and structures. Attention is 

 thus concentrated on their distinctive or specific characteristic, to 

 the temporary neglect of that usefulness which is the common or 

 generic characteristic of all artificial implements. 



Water falls by gravitation and, winding up the weights, which 

 also fall by gravitation, keeps in motion the pendulum which, so 

 long as it moves, beats seconds by gravitation. As gravitation is 

 said to be mechanical and " universal," it has seemed to some that 

 the clock thus placed must go on recording the flight of time, since 

 it is part of the mechanism of nature, and is independent of human 

 support or intervention. In other words, the automatism of the 

 clock that is, its independence of human users is held to show 

 that it is self-sustaining; but they who infer from this analogy that 

 the mechanism of nature is self-sustaining, while they deny that the 

 analogy shows that this mechanism has a purpose, seem to me to 

 play fast and loose with the analogy, and to reason like the dema- 

 gogue who tells the workman cheap money will raise his wages, and 

 bring down the price of those products of labor for which he spends 

 his wages. 



Must we not ask what we mean by the assertion that, once 

 started, the movement of the clock is automatic? What does the 

 word automatic mean in this connection? One thing it clearly 

 means: that the movement is independent of human users. It also 

 means that, the conditions being given, its movements may be 

 counted on with confidence. What else does it mean? Do we 

 find, in the clock or anywhere else, any ground for the belief that 

 its automatic movements, once started, are necessary or self-sustain- 



