90 The Scottish Naturalist. 



seem to be necessary to allow to them also the possession of 

 an immaterial and immortal soul as the subject or source of 

 these manifestations ; inasmuch as we could hardly, while hold- 

 ing the actions to be of the same kind, deny the agents in their 

 production to be of the same kind too. We could not maintain 

 the substances to be different, while we were obliged to allow 

 the qualities to be the same. Agassiz accordingly argues for 

 the existence in animals of such a soul. And it is long since 

 theologians have speculated on the possibility of meeting their 

 four-footed friends in heaven. 



Such is something of the question before us — a question not 

 more extensive in range of application and interest than it is 

 difficult of definite solution. The great savan and sceptic of Rot- 

 terdam, M. Bayle,who in his Historical Dictionary is led to touch 

 on this subject almost passim, says in one place, " Of all physical 

 subjects there is none more abstruse or perplexing than the soul 

 of brutes" (vol. viii. 273, English edition). In another place, he 

 says, " The actions of beasts are perhaps one of the most pro- 

 found abysses which our reason can exercise itself upon ; and 

 I am surprised that so few people perceive it" (vol. ii. 647). 

 Sir B. Brodie says, "There are few more interesting subjects of 

 inquiry than that of the moral and intellectual qualities of 

 animals; yet there are few of which we know so little." 



Plato and Aristotle have both recorded the dictum, that 

 astonishment is the commencement of philosophy (Theaet. and 

 Met. 1, 2, 9). And so it has been found here. The mystery 

 of the animal soul has called into exercise the wits of philosophy 

 for two and a half thousand years. Failing in one hand, it has 

 always been taken up afresh by another. Those philosophers 

 who have looked into the abyss, however, are more numerous 

 than those who have discovered that it was very deep, and far 

 more numerous still than those who have made any well- 

 managed attempt to reach the bottom. 



There are only three general views that can possibly be taken 

 of the question. And it will be found historically that they 

 have all, with various subordinate modifications, been espoused 

 and advocated. Each system of philosophy, in fact, has been 

 characterised, amongst its other distinctive marks, by one or 

 other of these views in reference to the animal soul. Com- 

 parative psychology is at least as old as comparative anatomy. 

 The possible views are these. It may be held, first, that 

 animals have a rational soul like man — the difference being 



