284 THE PHILOSOPHY OF BIOLOGY 



while admitting that the schoolgirl is acutely conscious 

 of her own multifarious activities. It is not that the 

 instinctive action displays a " finish," or perfection of 

 technique, that the deliberative action lacks : the comb 

 built by the wasp is not more perfect in its way than is 

 the doorway constructed by a skilled mason, or the 

 " buttonholes ' stitched by a seamstress. It is not 

 that instinctive actions are so absolutely stereotyped, 

 as is sometimes assumed, while intelligent actions grow 

 more perfect in their result by repetition : the work of 

 the insect or bird is often faulty and it is improved 

 by practice. The most obvious difference is that the 

 instinctive action is effective the very first time it is 

 performed, while the intelligent action only becomes 

 effective after it has been attempted several times, or 

 very many times, according to its difficulty. The flight 

 of the young swallow is effective inasmuch as it sustains 

 the bird in the air, but it is also an exceedingly difficult 

 series of muscular efforts which is at first clumsily 

 performed and which becomes more perfect by repeti- 

 tion. But the flight of an aeroplane, even now after 

 years of experiment, is not always effective, and ex- 

 hibits at its best all the imperfections of the flight of 

 the young swallow. Yet can we doubt that in time it 

 will exhibit all the ease and certainty and finish of the 

 flight of the bird ? 



The typical intelligently performed action is the 

 action of a tool, or of a part of the body which is used 

 for some other purpose than that which is indicated 

 by its immediate evolutionary history, or by its previous 

 use. The typical instinctively performed action is 

 always the action of a bodily organ, the structure and 

 immediate evolutionary history of which indicates 

 that it originated as an adaptation for the performance 

 of these particular actions, or category of actions. 



