Chapter 5
The Double Effect Of The Life Instinct
377. If we observe the effects produced by the soul's act, which diffused in extension animates the body, we see that some are subjective, like feeling, and others, as I have said, extrasubjective (cf. 374). We see that certain parts of the body are modified both subjectively and extrasubjectively, and are therefore the seat of both subjective and extrasubjective phenomena. However, other parts are seen to be modified only by particular, extrasubjective phenomena, and give no sign of subjective phenomena. The parts modified both subjectively and extrasubjectively are sensory parts, that is, organs of sensation; the others are the parts of the animal body which indicate only a share in life, but not feeling, at least not animal feeling.
It seems that the act by which the soul contributes to the production of feeling makes sensory only certain parts of the body, although it exerts its action on all parts, and tries, so to speak, to give them all feeling, but without success. This is probably due to lack of the necessary dispositions in the body itself rather than the direct weakness in the activity of the life-giving act, which is naturally inexhaustible.
378. Some physiologists posit a hidden sensitivity in all parts of the body. If this opinion had any foundation (and I believe it has, provided `hidden sensitivity' is understood solely as `not belonging to the individual feeling which constitutes what is animal'), we would no longer have any difficulty in explaining the fact under discussion. We could correctly suppose that the activity of the individual instinct, as it tried to join to itself and dominate every partial feeling of the animal body, would contribute to the production of the extrasubjective phenomena which all parts of a living body with their varying capacity for stimulation offer to our observation.
Such a supposition receives firm support from all those facts which show that even naturally insensitive parts manifest feeling under certain circumstances and when acted on by certain agents. Thus, we can say that extrasubjective phenomena even when lacking feeling can be considered as signs of certain dispositions of the parts which by the dispositions are prepared for becoming sensory.(177)
This opinion would be further strengthened if we could verify whether the passions were situated not in the cerebral nerves but in parts entirely devoid of feeling. It is claimed that the brain is never affected by passions. But 1. passions certainly show their effects in the organs of circulation, respiration, digestion, secretion, exhalation and absorption; 2. it is equally certain that passions are not accompanied by feelings of surfaces, such as those caused by external impressions, but of solids, such as internal feelings and the fundamental feeling itself; 3. it is also certain that we acknowledge these feelings to be located in the region of the organs just mentioned. `Gesture, as a mute expression of our feeling and mind, is a convincing proof of this,' says Bichat appropriately. `Thus, in order to indicate an intellective phenomenon related to memory, imagination, judgment, etc., our hand moves involuntarily to our head, whereas to express love, joy, sadness, hate, it goes to the region of the heart, stomach and bowels. It would be a mistake for an actor speaking about sorrow to gesture to his head, and when speaking about some bright idea to gesture to his heart. He would bring down on himself the ridicule we sense but cannot explain.'(178) Feeling connected with passions is therefore located in organs considered as non-sensory.
This fact would greatly help us in showing that the act by which the soul
vivifies what are considered unfeeling parts of the body is the very act that
produces feeling, which here is either less observable or follows other laws.(179)
Other facts confirm the teaching I have put forward, facts which are supported
by the authority of well-known writers, and should be further verified.
The first fact, attested by Dr. Bertrand in his Trattato sopra il Sonnambolismo, is that in somnambulists `organic sensibility' (we would say "organic vitality") `is heightened and changed into animal sensibility'.
The second fact, which resembles the first and is corroborated by several writers, especially German writers, is that through the action of animal magnetism human beings fall into a kind of sleep in which organic vitality is changed into sensoriness. Moreover, the same people feel and know all the internal parts of their body and the relevant remedies for the diseases affecting the parts.
379. We conclude: the life instinct co-operates with organic life and is the source of sensory life. Organic life is equally proper to all parts of the animal body; sensory life, as far as can be ascertained, is proper only to certain determined parts.
Notes
(177) It will be helpful to recall here Tommasini's opinion about the relationship between muscles and nerves. He considers muscles as a kind of expansion of the nerves, which accept other elements, especially fibre.
(178) Ricerche fisiologiche intorno alla vita ed alla morte, pt. 1, art. 6, §2.
(179) Cuvier attributes irritability itself to the nerves and unhesitatingly affirms that `the internal network of the nervous system exercises other functions, of which the animal is unaware and which are independent of its will. These functions impart the necessary irritability to the fibres covering the internal organs and vessels so that the fibres can act in accord with their purpose and play a part to some extent in all secretions and other vital functions' (cf. his article, Animali, in the Dizionario delle scienze naturali ecc.).