ii.] THE NATURE OF INSTINCT 167 



of histological elements belonging to different tissues more 

 or less akin. In both cases there are manifold variations 

 on one and the same theme. The constancy of the theme 

 is manifest, however, and the variations only fit it to the 

 diversity of the circumstances. 



Now, in both cases, in the instinct of the animal and 

 in the vital properties of the cell, the same knowledge 

 and the same ignorance are shown. All goes on as if 

 the cell knew, of the other cells, what concerns itself; 

 as if the animal knew, of the other animals, what it can 

 utilize — all else remaining in shade. It seems as if life, 

 as soon as it has become bound up in a species, is cut off 

 from the rest of its own work, save at one or two points 

 that are of vital concern to the species just arisen. Is it 

 not plain that life goes to work here exactly like conscious- 

 ness, exactly like memory? We trail behind us, unawares, 

 the whole of our past; but our memory pours into the 

 present only the odd recollection or two that in some 

 way complete our present situation. Thus the instinctive 

 knowledge which one species possesses of another on a 

 certain particular point has its root in the very unity of 

 life, which is, to use the expression of an ancient philoso- 

 pher, a "whole sympathetic to itself ." It is impossible to 

 consider some of the special instincts of the animal and of 

 the plant, evidently arisen in extraordinary circumstances, 

 without relating them to those recollections, seemingly 

 forgotten, which spring up suddenly under the pressure 

 of an urgent need. 



No doubt many secondary instincts, and also many 

 varieties of primary instinct, admit of a scientific ex- 

 planation. Yet it is doubtful whether science, with 

 its present methods of explanation, will ever succeed in 

 analyzing instinct completely. The reason is that in- 

 stinct and intelligence are two divergent developments 



