NECESSARY TRUTHS— EFFECTS OF EXPERIENCE. 627 



The first mode is called by Mr. Spencer direct, the 

 second indirect, equilibration. Both equilibrations must 

 of course be natural and physical processes, but they 

 belong to entirely different physical spheres. The direct 

 influences are obvious and accessible things. The causes 

 of variation in the young are, on the other hand, molecular 

 and hidden. The direct influences are the animal's ' ex- 

 periences,' in the widest sense of the term. Where what 

 is influenced by them is the mental organism, they are con- 

 scious experiences, and become the objects as well as the 

 causes of their effects. That is, the effect consists in a ten- 

 dency of the experience itself to be remembered, or to have 

 its elements thereafter coupled in imagination just as they 

 were coupled in the experience. In the diagram these ex- 

 periences are represented by the o's exclusively. The x's, 

 on the other hand, stand for the indirect causes of mental 

 modification — causes of which we are not immediately con- 

 scious as such, and which are not the direct objects of the 

 effects they produce. Some of them are molecular acci- 

 dents before birth ; some of them are collateral and remote 

 combinations, unintended combinations, one might say, of 

 more direct effects wrought in the unstable and intricate 

 brain-tissue. Such a result is unquestionably the suscepti- 

 bility to music, which some individuals possess at the pres- 

 ent day. It has no zoological utility ; it corresponds to nc 

 object in the natural environment ; it is a pure incident oJ 

 having a hearing organ, an incident depending on such in- 

 stable and inessential conditions that one brother may have 

 it and another brother not. Just so with the susceptibility 

 to sea-sickness, which, so far from being engendered by 

 long experience of its ' object ' (if a heaving deck can be 

 called its object) is erelong annulled thereby. Our higher 

 aesthetic, moral, and intellectual life seems made up of 

 affections of this collateral and incidental sort, which have 

 entered the mind by the back stairs, as it were, or rather 

 have not entered the mind at all, but got surreptitiously born 

 in the house. No one can successfully treat of psychogene-^ 

 sis, or the factors of mental evolution, without distinguish- 

 ing between these two ways in which the mind is assailed. 



