FAULTS OF TERMINOLOGY. 17 



even to plants; or its definition may be so restricted by 

 metaphysicians as to be applicable only to man. 



2. Sense and sensation, sensibility and sensitiveness, are 

 constantly confounded. Thus the late Dr. Baird, of the 

 British Museum, used the term * sensibility/ instead of 

 ' sensitiveness ' or ' susceptibility,' in speaking of the effects 

 of weather changes on animals. 



3. Irritability is frequently used by physiologists, in a 

 strictly scientific sense, as synonymous with mere sensitive- 

 ness to the influence of a stimulus that is, with mere irrito- 

 or excito-contractility as it exist^ even in plants while the 

 general public understand by it irascibility (of temper), and 

 the physician frequently a certain morbid state of brain and 

 nervous system. 



The faulty or unsatisfactory character of current defini- 

 tions of metaphysical terms is freely admitted by metaphysi- 

 cians themselves. The extreme difficulties of the definition 

 or application of the terms used in modern mental philosophy 

 have been pointed out by authors differing so much in their 

 various points of view as Darwin, Lewes, Laycock, and Bain. 

 Lewes, for instance, refers to the ' deplorable and inevitable 

 ambiguity of communication resulting from an absence of 

 strictly defined technical terms ' as constituting one of the 

 * many difficulties which lie in the way of psychological in- 

 vestigation.' On the other hand, Guizot has remarked that 

 ' the common meaning of a word is much more correct than 

 the scientific meaning, which has been given by a few persons 

 under the influence of a particular fact that has taken posses- 

 sion of the imagination.' Hence the propriety, as it appears 

 to me, of avoiding, when possible, in such a work as the 

 present all strictly metaphysical terms, or at least of 

 avoiding, where they must be introduced, all pedantic defini- 

 tions thereof, and of employing such popular designations as 

 mind, reason, intellect, instinct, consciousness, and so forth in 

 their ordinary, albeit vague and comprehensive, accepta- 

 tions. 



