Nevertheless there is nothing more common than the predominance of one system of the organic life over the other systems; this is sometimes the vascular, sometimes the pulmonary apparatus, at other times the organs of digestion, and the liver especially, have the greater degree of development, and decide on the particular temperament of the individual; but the cause of this sort of constitution depends on primitive organization, on the structure of the parts, on their conformation. Such superiority is by no means the effect of exercise or habit, for the fœtus and the child display the same phenomena, in as much reality though less apparently indeed, than adolescence, or manhood.
In the same way, the debility of any particular system of the internal functions, may depend either on original constitution, or on some accidental vice or disease, by which, while the others have remained untouched, its constitution may have been impaired.
Such then is the great difference of the two lives of the animal, with respect to inequality of perfection in the organs. In the animal life, the predominance or inferiority of one system, with relation to the others, depends almost entirely upon its activity or inertia, on its habitude of acting or not acting. In the organic life on the contrary, such states are immediately connected with the texture of the organs, and never with their education.
From hence also we have the reason why physical temperament, and moral character, are not susceptible of change from education, which so prodigiously modifies the actions of the animal life, for as we have seen, they both of them belong to the organic life.
The character is, if I may so express myself, the physiognomy of passions; temperament, that of the internal functions: now the one and the other being at all ages the same, having a direction which habitude and exercise can never alter, it is manifest that they must ever be withdrawn from the influence of education. The violence of the temperament may indeed be moderated, for the powers of the judgment, and reflection may be augmented, and the animal life strengthened in such way as to give it a capacity of resisting the impulses of the organic life; but to attempt an immediate alteration of the character, or of the passions, which are its habitual expressions, is an enterprise analogous to that of the physician, who should attempt to elevate or depress, (and that, for the entire life of the patient,) the ordinary contracting powers of the heart and arteries.
We should observe to such physician, that the circulation and respiration, are not under the dominion of the will; and that they cannot be modified excepting in passing into a state of disease. The same observation might be made to those, who imagine that the character, and consequently the passions may be modified.
FOOTNOTES:
[48] I am persuaded that the still very obscure theory of the fœtus might be elucidated by that of animals who have a similar organization. For example, in the frog, in whom but little blood goes through the lungs, the heart is a simple organ, with a single auricle and ventricle; there is a communication or rather continuity between the two systems, venous and arterial, whilst in the mammalia, the vessels in which the red blood circulates do not communicate with those which carry the black blood, except it be by the capillaries.
In the fœtus, the foramen ovale and the ductus arteriosus also render very evidently the arteries and veins continuous; in the fœtus the heart is likewise a simple organ, not forming, notwithstanding its partitions, but one cavity whilst it is double after birth. The two kinds of blood mix at this period, as in reptiles. Now, I shall prove hereafter, that in the child who has breathed, this mixture would soon be fatal; that the black blood, circulating in the arteries, would very quickly produce asphyxia in the animal. Whence arises then this difference? It cannot be studied in the fœtus; it is necessary perhaps to search for it in frogs, salamanders and other reptiles, which can, by their organization, be a long time deprived of air without dying, a phenomenon which approximates them to the mammalia while living in the womb of the mother. Till these very important researches are made, the history of respiration will be incomplete.
[49] This explanation is no doubt ingenious, but it is insufficient, since the causes which Bichat assigns for the rapidity of the growth of the fœtus cease entirely at the moment of birth, and yet the growth continues for a long time after to be as rapid.