According to the very wrong idea that one cannot reform  one’s  own  nature,  humans  think  they  are  to  be excused from putting forth the effort to correct their defects, in  which they deliberately delight, or  which would require too much perseverance to emend. It is thus, for example, that individuals inclined toward anger nearly always blame it on their temperament.  Before regarding themselves as blameworthy, they blame their faults on their body, thus accusing God for their misdeeds. This is a further consequence of the pride that may be found mixed in with all their imperfections.

Of course, there are temperaments that  lend themselves more than others to violence, just as there are more flexible muscles that lend themselves better to acts of strength. Nonetheless, do not believe that the primary cause of anger is to be found there; rather, be convinced that a peace-loving spirit, even in an ill-tempered body, will always be peace-loving, whereas a violent spirit in a lymphatic body will not thereby be meeker. Instead, the violence will only take on a different character. By not having a suitable organism to second its violence, anger will be more concentrated, whereas in the former instance, it will be more expansive.

Thus, the body does not cause anger in persons who do not already have it, just as it does not cause the other vices. All virtues and all vices are inherent to the spirit. Otherwise, where would the merit and responsibility be? A physically handicapped person cannot make him or herself whole, because his or her spirit has nothing to do with it; but this person can change what is of the spirit if he or she has a firm will. My fellow Spiritists, does experience not show you how far the power of the will can go in light of the truly miraculous transformations that you see happening? So tell yourselves that humans do not remain  vice-prone unless they want to remain vice-prone; those who want to correct themselves always can. Otherwise, there would be no law of progress for human beings.

Hahnemann (Paris, 1863)