A synopsis of Goethe's 1813-1830 speculative discussions on the "soul", or theory of being existence continuity, which, for lack of a better word, he described in Aristotle-Leibnitz entelechy and or monad stylized speak.

“As to his view of the nature of the soul, Goethe was careful not to commit himself definitely in his writings, but in conversation he now and then uttered ideas.”

“There can be no thought of an annihilation in nature of such high psychic powers, nor under any conditions, for she is not wasteful of her capital. Wieland's soul is by nature a treasure, a real gem. Moreover, during the whole of his long life he did not use up these spiritual and beautiful talents, but increased them. A personal continuance of our soul after death by no means conflicts with the observations which I have made for many years concerning the constitution of our own beings and all those in nature. On the contrary, it seems to be an outcome of them and finds in them new confirmation.

How much or how little of a personality deserves to be preserved, is another question, and an affair which we must leave to God. At present I will only say this: I assume different classes and degrees of ultimate aboriginal elements of all beings which are, as it were, the initial points of all phenomena in nature. I might call them ‘souls’ because from them the animation of the whole proceeds. Perhaps I had better call them monads. Let me retain this term of Leibnitz, because it expresses the simplicity of these simplest beings and there might be no better name. Some of these monads or initial points, experience teaches, are so small and so insignificant that they are fit only for a subordinate service and existence. Others however are quite strong and powerful.

All monads are by nature so indestructible that they can not stop or lose their activity at the moment of dissolution, but must continue it in the very same moment. Thus they only part from their old relations in order to enter at once into new ones. In this change all depends on the power of intention which resides in this or that monad. Each monad proceeds to whithersoever it belongs, into the water, into the air, into the earth, into the fire, into the stars, yea the secret tendency which conducts it thither, contains at the same time the secret of its future destiny. Any thought of annihilation is quite excluded.

Should we venture on suppositions, I really do not understand what could prevent the monad to which we owe the appearance of Wieland on our planet to enter in its new state of existence into the highest combination of this universe. By its diligence, its zeal, its genius, through which it has incorporated into its own existence so many historical states, it is entitled to anything. I should not be astonished at all should I, after millenniums, meet Wieland again as a star of the first magnitude. Then I should see him and bear witness how he with his dear light would gladden and quicken everything that would come near him.

To bring light and clearness into the nebular existence of some comet should be deemed a joyous task for a monad such as the one of our Wieland! Considering the eternity of this universe of ours, no other duty, generally speaking, can be assumed for monads than that they in their turn should partake of the joys of the gods as blessed creative powers. They are conversant with the becoming of creation. Whether called or uncalled, they come by themselves from all sides, on all paths, from the mountains, from the oceans, from the stars. Who can prevent them? I am sure that I, such as you see me here, have lived a thousand times, and hope to come again another thousand times.”

A rendition of Plato’s split soul theory, in regards to the hypothetical origin of humans, employed by Goethe in his Elective Affinities (P1:C5), via alternate side headache logic, that the characters (or reactants) Eduard and Ottilie are long lost soul mates destined for each other.

“There is a great lack of lucidity in these sentences. On the one hand the monads are the simplest realities, a kind of atoms, which belong to fire, water, earth, and other elementary existences; on the other hand, they are psychic agencies, and are introduced to personify the law that sways the formation of a nebula into a planetary system; and again they are assumed to be psychic entities. Perhaps some monads are thought to be chemical atoms and others psychic powers; and the latter, after the fashion of the Greek deities, are expected to do the work of the natural laws. Such thoughts are poetry, not science; fiction, not psychological facts; mythology, not philosophy. If we knew Goethe from this passage alone we would say that he was a mystic. We grant that he had a mystic vein whenever he happened to speak or refer to the soul, but even here he disliked the excrescences of mysticism.”

“In the sympathy which binds our souls, in bygone ages, I feel, you must have been either my sister or my wife.”

— Johann Goethe (c.1774), Poem to Charlotte von Stein [1]

“It would be quite impossible for a thinking being to entertain the idea of its own non-existence or the discontinuance of its thought and life. Accordingly everyone carried a proof of his own immortality quite immediately in himself, but as soon as he tried to commit himself to objective statements, as soon as he would venture to come out with it, as soon as he wanted to prove dogmatically or comprehend a personal continuance, as soon as he would bolster up this inner observation in a commonplace way, he would lose himself in contradictions.”

— Johann Goethe (1823), Conversation with Chancellor von Mueller and Herrn von Riemer, Oct 19 [1]

“To be engrossed with the ideas of immortality is only for the leisure classes, and especially for women who have nothing to do. An able man who needs to make himself useful here, and who accordingly has to exert himself daily, to struggle and to work, leaves the future world alone and is active and useful in this one.”

— Johann Goethe (1824), Conversation with Chancellor von Mueller, Feb 25 [1]

Wagner, a famed sorcerer's former student, creating Homunculus in the chemical laboratory using fire (or heat) and some type of chemical apparatus, as described in Goethe's 1832 Faust part II (see: laboratory produced life); in his talk with Eckermann, Goethe is supposed to have said that Homunculus is virtually the same as the Leibnizian entelechy or monad, according to John Williams. [3]

“Each entelechy is a piece of eternity, and those few years during which it is joined to its terrestrial body do not make it old.”

— Johann Goethe (1828), Conversation with Johann Eckermann, Mar 11 [1]

“I do not doubt our continuance, for nature cannot do without continuity; but we are not all immortal in the same way, and in order to manifest himself as a great entelechy, a man must first be one.”

— Johann Goethe (1829), “Conversation with Johann Eckermann”, Sep 1 [1]

“The persistence of the individual and the fact that man rejects what does not agree with him, are proofs to me that such a thing as an entelechy exists. Leibnitz cherished similar ideas concerning such independent entities, only that what we call ‘entelechy’ he called ‘monads’.”

— Johann Goethe (1830), “Conversation with [add]”, Mar 30 [1]

“Goethe's conversation with Falk is perhaps the most important passage to be quoted on the mooted topic, and it may be well to bear in mind that it was Falk and not Goethe who wrote these sentences, and that they therefore must be used with discretion.”

— Paul Carus (1910), “Goethe’s Soul Conception” (pg. 750) [1]