At prehistoric times, our ancestors tried to localize the useful powers and harmful powers which seemed to them associated to beings and to things.

So, exam of fossils, reveals that during the Neolithic, skull was probably recognized as main "source" of "mysterious power" which acts in us and by us.

Much more later, for the mesopotamian priests (2.000 years BC), even for sumerian priests (- 4.000 years),
for this observers of beings's behavior before death because they was regulators of animals sacrifices, and even of men,
this power has been recognized in the internal organs, more exactly in gall-bladder.

In Egypt, probably about 3.000 years before J.C., other "specificities" of the man's power are recognized in :
the heart for the knowledge and intelligence,
the chest for the courage,
the belly for the physical activities.

As for Bible's writers, influenced by the surrounding cultures, they even will prescribe :
"However, by no means eat the blood, for the blood is life itself ; you must not eat the life with the meat. You must not eat it ; You must pour it out on the ground like water. "(cf. Dt. 12, 23-24).

But if we consider the french bible's version :
"Seulement tu veilleras à ne pas manger le sang, car le sang, c’est l’âme ; tu ne mangeras donc pas l’âme avec la viande. Tu ne le mangeras pas mais tu le verseras par terre comme de l’eau." (cf. Dt. 12, 23-24),
we don’t know if expression "the blood is life itself " corresponds to concepts which prevailed in Israel six centuries before J. C..
Blood, was it the life or soul ?
What is the exegete who can answer ?

At the same epoch, an exceptional epoch in the humanity's history, Pythagoras (- 572, - 497) will imagine two essential entities,
- the "Phrenes" (intelligence) in brain,
- and the "Thumos" (active part of the soul) in heart, of entities which he considered as vital principles.
We speak of this epoch as exceptional because it was also the one of Lao-Tsu (- 570, - 490) and Confucius (- 551, - 479. 

Afterward, Democritus (- 460, - 370) will privilege brain where according to him, is intelligence, whereas Hippocrates (- 460, - 377) will consider the vital principles as conveyed by the air.
Short digression : Democritus, having meditated on very small particles which compose dust "propounded" the atom notion ; let's beware however to easy popularizations which try to persuade us that in the antique times, men already knew this inward structure of the inert matter, as our physicists.

Aristotle (- 384, - 322), inspired by Hippocrates, will see in the nerves, the vectors in body of vital principles which are within air,
of the vital principles that he named "entelechie" :
"What naturally moves body, what he names entelechie, a cold invention as no other one, because he does not speak of «essence», nor of the origin, nor of the soul's nature, but remarks only his effect." (cf. Aristotle quoted by Michel de Montaigne - Essays, II, 12).

We can moreover compare the entelechie to,
- the substance according to Descartes,
- the monad which would be for Leibniz (1646 - 1716), active substance of the beings and things,
- the creative entity of transcendent order (of divine character), henceforth credible due to recent knowledges.

Nevertheless, the first nobility letters of the soul and Spirit, were written by the Platonists and Neoplatonists :

" …What is producing fire by giving its shape, must act according to a reason (the "logos") and only a soul can be able of producing fire, that is at the same moment, a life and formal reason (the "logos"), both being the same thing.
That is why also Plato says that in each of these elements, there is a soul, and this soul, he does not understand it otherwise than as a soul producing exactly this sensible fire." (cf. Plotinus - Treatise 38 - 11, 40).

More precisely, the neoplatonists were seeing in soul an emanation of the Spirit, and thus, they were considering that soul had spiritual powers.
For them, it was also necessary :
"That the Spirit lives all the lives and with all their modes and that there was nothing that he is not living, ... It is in the spirit's nature from transforming himself in all things." (cf. Plotinus - Treatise 38 – 15 et 25).

It has had too, the wide-spread concept of pneuma.

According to Erasistrate of Alexandria, doctor (- 320 ? - 250), vital energy necessary to body (pneuma zoticon) is going to heart by the pulmonary veins, whereas spiritual energy necessary to the psychism (pneuma psychicon) is going to brain through the nerves,
a theory resumed and completed, much later, by Galien (131, 201).

Indeed, Galien, a greek doctor whose notices made authority until the XVII century, considering all the animal and psychic functions of the beings, imagined a pneuma composed of :
- a pneuma physicon inherent to food and intended for the liver where would be mysterious physical power who animates body,
- a pneuma zoticon conveyed by the veins to heart, who would be mediator between power stimulating the body and power of the feelings and passions,
- a pneuma psychicon transported in the brain by the blood, who would be necessary for the intelligence and faculties.

This pneuma, how did it be one and multiple ?
Galien refrained from specifying it ; very likely however, he was under influence of neoplatonists.

Also let’s quote Philon of Alexandria (a Greek philosopher of Jewish confession, towards - 20, 45), for who, as the Essenes, the soul's material part is blood, soul which he was considering nevertheless composed of air and of fire. (cf. Life of Moses - 1, 9).
This follower of the metempsychosis, will consider even the space which surrounds us, as the permanent stay of the souls before their embodiment, and will imagine in the tops of the sky, the realm of the spirits.

Afterward, some christian religious people in charge, having taken control of the " medical sciences ", will try to integrate into their faiths, metaphysical theories founded on the dissections's study,
of essays that will lead the bishops to forbid medicine's practice by high clergy (synod of Reims, 1131) ; pope Innocent III (1160, 1216) will condemn even, doctors who work without the monks presence.

However, don’t be surprised by these behaviors because to this epoch, the knowledges were very elementary and notions of vital energy, of pneuma, of soul and of spirit, were particularly vague.
The examples abound :

- Léonard de Vinci (1452, 1519 ), according to autopsies which he often practised, was believing that there is transformation of the vital spirit who is coming from heart, in an animal spirit, in the brain's bottom : the rete mirabilis,
- Berengario of Carpi (1460 ? – 1530 ?), Bologna, will consider that the "vital spirit" become an "animal spirit" to contact of the ventricular secretions,
- André Vésale (1514 - 1564) who was flemish, father of the modern anatomy, condemned by the Inquisition, will try to show that the cerebral ventricles are intended for conservation of "animal spirit",
- André Césalpin (1519 - 1603 ),an italian doctor, for reason that heart is the first organ which emerges from embryo, will recognize in heart the seat of the vegetative soul,
- Van Helmont (1577 - 1644), a flemish doctor, will imagine an intangible entity, the archée supposed be sensitive (sensory) soul who is in charge of body's functions ; he will place her even, at stomach's level.

Descartes (1596 - 1650), too, will mislead :

"But, in my judgment, those who will often think in their spirit, to things which I wrote in my second Meditation, will be persuaded easily that spirit is not distinguished from body by a single fiction or an abstraction of the understanding, but that the spirit is known as a different thing, because it is such indeed …,
however I shall still say here that it seems to me that it is the very remarkable thing, that no movement can be made, either in animals body, or even in ours, if these bodies have not in them all organs and instruments which enable these same movements, movements which could be also carried out in a machine ; in such a manner that, even in us, it is not spirit (or soul) that moves at once the outside members, but only he can determine course of this very subtle liquor which we name "animal spirits", this liquor which is going constantly of the heart by the brain into the muscles, and which is cause of all our members's movements … (cf. The Fourth Answer, 178).

These various comprehensions of the spirit, soul and organs, reveal, obviously, influence of knowledges in philosophic reasoning, ipso facto, in theological debate,
and as a consequence,that erroneous world's comprehensions condemn, for ever, numerous speeches, even expressed by illustrious personages.

Denis Diderot (1713 - 1784) and Jean d’Alembert (1717 - 1783) have been conscious of it.
In an Encyclopedia which resumes all knowledges to their epoch, they concluded :
"Not only we don't know our soul, nor the way by which she acts on the material organs, but also in these organs, we can perceive no disposition which shows that this one rather that another, is soul's seat.".

There will be, still, some attempts of localization of the soul and spirit, but on this matter and as for the primordial causes, since the XIXth century the scientists with their mechanical world's understanding, are confining the philosophers and theologians into a remarkable non-creativity.

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