THE INBORN POTENTIALITY OF THE CHILD 319 



been devised to exhibit the bio-physical and bio-chemical con- 

 ditions underlying normal physiological processes in the organ 

 of mind; and until we have some conception of this we cannot 

 explain such abnormal temperamental and disordered mental 

 conditions due to functional derangement of the complex 

 mechanism of mind. 



We know, however, that " like tends to beget like," and 

 everybody recognises the potential value to the individual of 

 coming from a mentally sound and good stock. 



The inborn mental potentiality of the child may be sound, 

 partially sound, or unstable or totally unsound. A careful 

 inquiry into the family histories of the progenitors and the 

 collateral members of the ancestral stocks will in the great 

 majority of cases show that a child born sound in mind and body 

 is begotten by parents sound in mind and body themselves, 

 whose stocks are free from any neuropathic or physical taint. 

 Such a child with a good inheritance is very unlikely to suffer in 

 later life with feeble-mindedness, epilepsy, insanity, or functional 

 nervous disease. Occasionally, however, from some inexplicable 

 cause parents of sound stocks may beget an idiot or imbecile 

 child, or a child who in later life becomes insane or epileptic. 

 But every effect owns a cause ; although we may not have 

 discovered it, and it is unscientific to speak of it as a sport. It 

 may occur as a result of a latent morbid tendency in the germ 

 plasm of the two stocks, as we know frequently happens in 

 consanguineous marriages, when both stocks are apparently 

 healthy, yet one or more of the offspring are mentally or physic- 

 ally unsound. A partially sound or unstable inborn mental 

 constitution is usually inherited, and careful inquiry generally 

 shows one of the parents or some other member of the parental 

 stocks to have been mentally unsound or unstable. The child 

 may give evidence of mental defect by being dull and backward 

 in learning, or it may exhibit fits of uncontrollable temper with- 

 out cause, or other signs of nervous irritability such as convulsive 

 attacks which may be precursors of true epilepsy. If the child 

 escapes any distinct morbid manifestation during childhood, 

 there is a danger of its showing vicious tendencies later, or 

 developing insanity or epilepsy at the period of adolescence 

 when the sexual instinct is aroused and new desires and passions 

 stimulate the brain to a new activity. It seems that a mental 

 breakdown is also liable to occur in such individuals from 



