278 THE PHILOSOPHY OF BIOLOGY 



meaning. Consciousness is not a concept to be dealt 

 with in any process of reasoning, it is not even some- 

 thing felt in the way in which we speak of the feelings 

 of pain, or light, or hunger : these are all states of our 

 consciousness. The difference in ourselves, says Ladd, 

 when we are sunk in sound dreamless sleep, and v/hen 

 we are in full waking activity, that is consciousness. 

 If we reason about organisms and their activities as 

 we do about inorganic things we have no right to speak 

 about consciousness, for outside our own Ego it has 

 no existence. The acting animal is only a body, or a 

 system of bodies, moving in nature, and all its activities 

 are to be described by a system of generalised force and 

 position co-ordinates with reference to some arbitrarily 

 chosen point of space. " This animal machine," says 

 a zoologist, writing about instinct, " which I call my 

 wife, exhibits certain facial contortions and emits 

 certain articulate sounds which correspond with those 

 emitted by myself when I have a headache, but I have 

 no right to say that she has a headache." This kind of 

 argument does not appear to be capable of refutation 

 except, perhaps, by the domestic conflicts which it 

 would usually evoke if applied in such cases as that 

 quoted. In a description of nature by the methods 

 and symbolism of science we see only systems of mole- 

 cules in motion, and in those systems which we describe 

 as organisms the motions are only more complex than 

 they are in inorganic systems. Such is the method of 

 science, as irrefutable in the study of the organism as 

 we know that it is false. Valid in pure speculation 

 according to the methods of the intellect it would never- 

 theless be absurd in the everyday affairs of common 

 civilised life ; and the scientific man who applies it in 

 his writing would nevertheless hesitate to apply it in 

 the affairs of his own household. 



