282 2 he Scottish Naturalist. 



there can be only one kind of intelligent souls among earthly 

 creatures. 



The main point at issue, then, is clear and definite. It 

 is this — Is the animal soul of the same kind as the human ? 



As to the means, or even the possibility, I may say, of pursu- 

 ing an investigation into the subject, I would wish to emphasize 

 a point to which I formerly alluded. It is a point on which we 

 find able writers taking diametrically opposite sides. It refers 

 to the relation between the special psychology of man and 

 comparative psychology — which of the two is the basis for the 

 study of the other. It seems to me that you could not state 

 the problem of the animal soul in airy workable manner, without 

 pre-supposing and employing a knowledge of the human soul. 

 It must be obvious that if it could be stated, it could not be 

 worked without that knowledge. Action so mysterious as animal 

 action we can hope to understand only by help of the analogy 

 of other action, the nature and cause of which is more acces- 

 sible, i.e., immediately accessible in its inner nature, and that is 

 our own action. No doubt, if you say the human mind is more 

 complex than the animal, there is a rule of general method that 

 might seem to condemn the procedure of beginning as I have 

 said. " The order of investigation must in all sciences be from 

 the simple to the complex!" (Cald. Hdb. 3.) "It has come 

 to be a recognised action in science that the study of the simple 

 should precede that of the complex " are the opening words of 

 Dr. Lindsay's paper in the "Journal of Mental Science;" and 

 he makes " the substitution of a better state of matters," in 

 reference to our knowledge of the animal and human soul, 

 conditional on " beginning our studies on mind with its genesis 

 or rudiments in the simplest forms of animals, tracing its 

 gradual progress from simplicity to complexity." But clearly 

 this rule will hold only when the investigator's instruments of 

 research are equally good for the simple and for the complex. 



For if this is not the case, the rule must give place to another 

 — begin ivhere your instruments and means are most adequate 

 and facile of application. Besides, going by the rule of the 

 simplest first in this case, supposes that the physiological method 

 of search alone is to be followed, not the introspective — a 

 method which Comte has declared to be imposible. But when 

 the object of search is mind, it is better to designate at once as 

 it deserves the proscription of the introspective or psychological 

 method, and say, such proscription is sheer nonsense. It is 



