296 THE DOCTRINE OF DESCENT, 
certainly rescuing the other side of the dualism. But 
here, too, we will not be defrauded of our say and our 
own opinion. The mental powers of man, in their origin, 
growth, and effects, are likewise susceptible of investiga- 
tion, and psychology only too long thought it possible 
to elude physiology. Let us, therefore, proceed in good 
heart to a short examination. 
It is universally admitted that a certain relationship, 
or analogy, exists in the psychical capacity of the higher 
animals andman. Reason alone, it is said —the essence 
of psychical agencies by which man attains self-cdn- 
sciousness, and rises to abstract conceptions, combines 
ideas, especially religious ideas, and lives in art and 
science,—this the animal does not possess. We reply 
that animals certainly do not possess this degree of 
mental development, but neither does man possess it 
in lower phases of evolution. 
The soul of the new-born infant is, in its manifestations, 
in no way different from that of the young animal; 
these manifestations are the functions of the infantine 
nervous system; with this they grow and are developed 
together with speech. The grade to which this de- 
velopment rises is generally dependent on the preceding 
generations. The psychical capacities of each indi- 
vidual bear the family type, and are determined by 
the laws of heredity. For it is simply untrue that, 
independently of colour and descent, each man, under 
conditions otherwise alike, may attain a like pitch of 
mental development. As a proof of this primary 
equality of mankind, single instances of gifted 
negroes and Indians are held up to us. But these 
have behind them unnumbered generations practised 
