'These oxygen, nitrogen, hydrogen and carbon, which are there in the human body, explain so little the coexistence of a soul in him, so little in the end the faculty of imagining in the latter that one can regard every such attempt to explain it rightly to the greatest delusions of a futile human effort.
'In addition, these chemical elements are the ever-changing ones: they enter into the assimilation circleof the body and retire again. Yes, after the course of a certain time, this external body, this product of their composition, is being so completely restored,that not even the smallest part of this oldbody stays; that a completely new body is available.
Nevertheless, the same body remains throughout the duration of our life, both in the outer type and after thebasic character of its organic constitution, the one and same during this constant transformation of his substances (see § 43, where we pointed to the importance of this fact). In the material elements therefore, the truly enduring, the unifying formprinciple of the body that works throughout the whole life, cannot be found. Neither can it be found in the mere combination, the 'mixture'of these elements; because it would be, as we likewise as above showed, a logical contradiction, to create something new from mere combination, which is not present in any single constituent of this combination.
'So we are going to a second, essentially other cause in the body. That persistent and unifying part in it can not be found in the its substances, it cannot be anything material at all; because it is absolutely overpowering to them, by forcing their dissimilarity, 'assimilating' them, to the harmony of the external physical appearanceand by keeping this unity upright throughout life. That is it can be thought only as 'force'; as a force but without a doubtattached to a real substrate, without whichthought the 'power' would sink to an idealistic nonsense. Nevertheless, this substrate cannot also be a substance, a simple element; otherwise we would not be able to overcome the old familiar circle of contradictions. How we have to describe on the other hand the nature of this substrate will become clear, when we trace further the nature of that force.
'This unifying, this real 'bond' of the outer body, which the ancients already have known as 'dynamis', as cohesive power, is effectively present in all its parts, and abolishes at the same time, as an inner cohesive, the separating meaning of all its spatial parts. We have to ascribe to it this'dynamic presence' in the body, which announced itself as the first (most universal) attribute of the soul (§ 82). Because at the same time it is actually the persistence in the metabolism, it is the true, inner,
invisible, but in all visible materiality present body. The other side, the external appearance of the body, formed from incessant metabolism, may from now on be called 'body', which is, truly not persistent and notone, the mere effect or the afterimage from this inner body, who throws it into the changing metabolism, just as the magnetic force develops a seemingly dense body out of the partsof the iron stuff, that spatters in all directions though, when it is deprived of its binding force.
'This doctrine of the 'inner' body, of the 'pneumatic organism’ is ancient and has been developed at all times in a variety of ways. In contemporary science it is being treated more like a possibly ingenious hypothesisthan as a strictly proven physiological fact, to which the newer research could come. Already the oldestand, as will be seen below, not at all meaningless folkbelief meant this inward, everlasting‘body’, could let the human being live on after death as a shadowy image of his personality (eidola, manes, lemures) and sometimes let him reappear.
What Plato semi-mythically taught about this existence after death is wellknown; but even Hippocrates recognised already in the outer body the presence of a harmonising activity (enormon) that reigns the various bodily processes and unifies them.
And we can find in Aristotle a prudent exploration of this concept. Each soul, he teaches, has obtained for the immediate substratum of the effect on his body a substance that is another one and is more perfect than the four elements of which, according to its doctrine, every organic body is composed. This would be the cause of the warmth of life, dwelling in the seed of every individual being, and being the fertilizer of it; In it lies the principle of procreation as well as of nutrition, which Aristotle otherwise declares not to be considered as physical psyche. According to its origin, however, it is an etheric substance, akin to that of the stars, which, according to various degrees of purity, are contained in all living beings, and are formed to the highest purity at first in man. Thus this philosophical thesis forms at least a scientific point of reference for the later doctrine of the 'pneumatic body', which propagated through Neo-Platonism, the Kabbalah and Christian mysticism to the theosophical natural scientists of the new epoch and which remained a ferment for deeper researchto the present day. This spiritual body is the 'Nephesh' of the Kabbalah, the mediator of the material earthly body with the inner spiritual life. Paracelsus calls it - even ‘aristotelising’, if one wishes -the 'sidereal' or 'astral body', opposite to the earthly elemental body, which we lose in death;whereas the latter is the truly immortal or immortalising of the human being. He describes it as the 'magnet' of the microcosm around which everything in man gathers and from which all effects flow.’ (Translation in English MM)
Immanuel Hermann FichteSpiritual body, etheric body or astral body ... A philosophical attempt by Immanuel Hermann Fichte by Mieke Mosmuller