208 THE FOUNDATIONS OF ZOOLOGY 



only to suppose," he says, "that the seeming duality is relative 

 to our modes of apprehension ; and, therefore, that any change 

 taking place in the mind, and any change taking place in the 

 brain, are not two changes, but one change." " To suppose mind 

 the cause of motion, or motion the cause of mind, is equally to 

 suppose that which is neither true nor untrue, but nonsensical." 

 ** It is equally nonsense to speak of mental action causing cerebral 

 action, or ' of cerebral action causing mental action, nonsense of 

 the same kind as it would be to speak of the ' Pickwick Papers ' 

 causing a storm at sea, or the eruption of a volcano causing the 

 forty-seventh proposition of the first book of Euclid." 



I am myself quite unable to see how one who holds it 

 nonsense to suppose mind can cause motion, can for a moment 

 think the origin of a reflex act or automatic response would be 

 easier to understand through proof that it was, at one time, 

 accompanied by conscious intelligence. Neither they who know 

 no reason why thought should not, some day, be reduced to 

 mechanics, nor they who believe, with Romanes, that this has 

 already been accomplished, can, in consistency, believe that use 

 directed by intelligence can either bring about adaptive structures, 

 or supply to natural selection even the incipient stages of adaptive 

 modification, unless they attribute this adaptive influence to mere 

 use, in itself, and not to the guidance of use by intelligence. If 

 the Lamarckians tell us that this is their contention, and that it 

 is mere use in itself that brings about adaptive structures, is it 

 not obvious that, inasmuch as rational actions are, as a rule, more 

 complicated than those we call reflex, their origin is not easier, 

 but harder, to understand.? 



If we agree with Romanes that "what we know on the side 

 of mind as logical sequence is on the side of the nervous system, 

 nothing more than the passage of nervous energy through one 

 series of cells and fibres rather than another," how can practice 

 in logical reasoning bring about any of these cells or fibres or 

 direct nervous energy into one series rather than another, except 

 so far as adaptive mechanism for bringing this about already 

 exists } 



If "what we know as truth is merely the fact of the brain 

 vibrating in tune with nature," is the behef that natural know- 



