368 Appendix 
existence of stich an instinct is the need for the con- 
tinuance of the race. 
Finally, the fact that both animals and man now 
desire copulation or even certain secondary sexual rela- 
tions for their own sakes—hence independently of the 
act of the elimination of the germinal substance, perhaps 
even in default of any to eliminate,—this also, as we 
shall better appreciate later on, is only the consequence 
of the mnemonic law already mentioned of the substi- 
tution of the part for the whole, and of its derivative, 
the law of the transference of affective tendencies. Ac- 
cording to this law all phenomena that constantly ac- 
company the satisfaction of certain affectivities become 
also in their turn objects of desire, and all habits ac- 
quired for the satisfaction or in the satisfaction of cer- 
tain affectivities likewise become affective tendencies. 
If the sexual instinct also, on account of its origin, 
can be referred to the class of tendencies which serve to 
maintain the stationary physiological condition of the 
organism, then the above law is open to no exception 
as far as the fundamental organic tendencies are con- 
cerned. Hence we can sum it up in the following 
words: 
Every organism is a physiological system in a sta- 
tionary condition and tends to preserve this condition or 
to restore it as soon as it is disturbed by any variation 
occurring within or without the organism. This prop- 
erty constitutes the foundation and essence of all 
“needs,” of all “desires,” of all the most important 
organic “appetites.” All movements of approach or 
withdrawal, of attack of fight, of taking or rejecting, 
which animals make are only so many direct or in- 
direct consequences of this perfectly general tendency 
