INTRODUCTION. O 



training, and acting appropriately without consciousness of 

 the object aimed at. The word instinct is derived from 

 the Latin instinguere, to excite or to allure, and therefore 

 necessarily connotes an exciter or allurer. Therefore 

 Ccesalpinius says, very properly, from this point of view : 

 Deus est anima brutorum God is the mind of animals. 



It is evident that under such circumstances the question 

 of the mind of animals could never become a scientific 

 study ; scientific investigation of the intellectual and 

 emotional powers of animals in comparison with those of 

 man, in fact comparative psychology, was impossible. The 

 subject was either dealt with as a mere collection of curi- 

 osities, an innocent amusement, an intellectual pastime, or, 

 more usually, the purely theological standpoint was taken, 

 and the endeavor was made to use this theme as so many 

 similar ones drawn from Nature merely as an object of 

 pious wonder. 



The Cartesian theory had given rise to much controversy 

 in its time, and the hostile philosophy of Leibnitz, teaching 

 organic gradation and the unbroken unity of all living things, 

 both of men and of animals, had called up against it a host of 

 writers. The most important of these productions for our 

 position was the small work of Jenkin Thomasuis, published 

 in 1713, who supported against Descartes and in the 

 spirit of his own time and of Leibnitz the immateriality, 

 and therefore the immortality, of the animal soul. The 

 German editor of the book, Professor Bajer, also declared 

 against instinct, and held that among the various opinions 

 of the learned on the mind of animals, that which saw in 

 animals the analogue of the human mind was the most 

 conformable to man's natural judgment, and the most use- 

 ful for throwing light on animal actions. In like fashion 

 Professor Reclam, another author on the same question 

 (" Body and Mind," 1850, p. 384), wrote very well : " We 

 therefore conclude that we ought entirely to give up the ex- 

 pression ' instinct,' for we only can and should apply it to 

 such actions of animals as we can explain in no other way, 

 and we ought, remembering Kepler's warning, to seek 

 for every other explanation before we use a word so inde- 

 finite and so apt to mislead." In fact, those who deny this, 

 and who will not compare the intellectual faculties of 

 animals with those of men, must renounce all scientific 



