See also how the passions which have their influence particularly over the internal organs, which especially affect those placed around the epigastric centre, the heart, the liver, the stomach, the spleen, &c. imprint on our motions an impetuosity, which the will cannot make us masters of. The internal organ affected re-acts upon the brain, this excited stimulates the muscles; they contract, and the will is almost nothing in this contraction. Observe the man, whom jealousy, hatred or rage agitates to the greatest degree; all his movements follow each other with an impetuosity which judgment reproves, but which the will cannot moderate, so much does the influence of the sympathetic affection of the brain predominate over that of the will. At other times the passions exhibit an opposite phenomenon. They are marked by a general weakness of all the muscular motions. In astonishment accompanied with grief, or in that in which is mixed a lively joy, the arms fall down as it is commonly expressed; the cerebral influx ceases almost entirely, and yet it is not to the brain that the influence of this passion is carried, it is to the epigastric centre, as is proved by the sudden contraction which is felt there. One of the epigastric organs has been affected; it has reacted upon the brain; this has been interrupted in part in its functions; the muscles feel it and theirs cease. In fear in which this phenomenon is observed, as the paleness of the skin indicates the languor of the circulating system, it may happen that the cerebral and muscular inaction arises in great measure from this, that there is not received a sufficient impulse from the heart, upon which the first influence of the passion is exerted, and which by this influence is retarded in its motions. Fear, it is said, takes away the legs, petrifies, &c.; these expressions, borrowed from vulgar language, indicate the effect of this passion on the muscles; but this effect is only secondary; the first influence has been upon the heart, the second upon the brain; it is not till after the other two that the muscles are affected. Hence how certain animals remain immoveable at the sight of that which is about to seize them for its prey. It is also to the sympathetic influence of the internal organs upon the brain, that should be attributed the motions of the fœtus, motions which the will does not direct; for the will is but a result of the intellectual phenomena; now these phenomena are nothing at this period of life. The internal functions then very active, suppose a great action in the liver, the heart, the spleen, &c.; now these organs in that way influence efficaciously the brain, and this in its turn puts the muscles in motion; so that the animal contractility is by no means voluntary in the fœtus; it does not begin to become so until the sensations have brought into action the phenomena of the understanding; until then, they must be compared to all those of which we have spoken above.