The Ideas

The alchemical homunculus

Behind the word lie very different texts, centuries apart: an Arabic book of magic, three passages in the corpus of Paracelsus, the recipe printed in 1572, a drawing of 1694 and a scene by Goethe. This page reads them one by one, with their dates, and separates what the texts say, what is disputed and what was added later, down to today’s viral videos and TV series. The biography of Paracelsus and the authorship of his works have a page of their own, linked below. The “homunculus” of neurology, the map of the body on the cerebral cortex, shares only the name; it gets a section near the end.

What a homunculus is, and what it is not

In its technical sense, a homunculus is a human being made outside a woman’s body; this meaning took shape in the 16th century in the writings that circulated under the name of Paracelsus. In classical Latin homunculus simply means a little man, or a person of little account, a diminutive of homo (Lewis and Short, A Latin Dictionary, 1879, s.v. “homunculus”, p. 860, Internet Archive). So if you ask “what is a homunculus in mythology?”, the answer is that it does not belong to ancient mythology: we have found neither the word in that sense nor a recipe in any Greek or Latin text of antiquity. There are earlier accounts of beings made by art, and they should not be confused with one another: the little man of a vision, the rational animals of an Arabic book of magic and the wax figurine of image magic.

Before Paracelsus: a vision and a book of magic

Zosimos of Panopolis (about 300 CE) recounts a series of dreams in his treatise “On Virtue”. In one, a priest called Ion, standing on a bowl-shaped altar, explains that he has been cut to pieces and burned, and Zosimos sees him turned into an ἀνθρωπάριον, a deformed “little man” (petit homme contrefait, in the French translation) who tears at his own flesh with his teeth; in the next dream another little man appears, a grey-haired barber (Berthelot and Ruelle, Collection des anciens alchimistes grecs, vol. II, Greek text, and vol. III, French translation, pp. 117-119, Internet Archive). He is a figure in a vision, not a manufactured being: nobody makes him, and there are no instructions for making him. For the author and his texts, see Zosimos of Panopolis.

The clearest technical forerunner is the Kitāb al-nawāmīs, an Arabic book of magical experiments, falsely attributed to Plato, that circulated in Latin as the Liber vaccae, the “Book of the Cow”. On the evidence gathered by Maaike van der Lugt, the original postdates Hunayn ibn Ishaq, who before 856 translated a work the book seems to refer to, and predates its citation in the Kitāb al-tajmīʿ of the Jābirian corpus, from the early 10th century. David Pingree attributed it to an author from Harran, a hypothesis Van der Lugt does not regard as proven, and placed its Latin translation in Spain, because it is cited by the Picatrix, which was written there. The oldest Latin manuscript dates from the late 12th or early 13th century (Van der Lugt, Traditio 64, 2009, pp. 229-277, notes 9, 12 and 15, DOI).

Its experiments aim to produce a rational animal from a cow, a monkey or another beast, or to generate bees: so Lynn Thorndike summed them up in 1923, as Van der Lugt notes. William of Auvergne cited it in the 1220s to condemn its mixtures: according to him, the book was called the “laws of Plato” because it went against the laws of nature (De legibus, ch. 12, transcribed by Van der Lugt, note 99). The historian William R. Newman treats it as the first technical precedent of the homunculus and thinks it very likely that Paracelsus knew it (according to the summary by Mary Baine Campbell, Republics of Letters 1, no. 2; Newman, Promethean Ambitions, 2004, ch. 4).

At the end of the 15th century, Giovanni Pico della Mirandola denied that it was by Plato. In book I of his Disputationes adversus astrologiam divinatricem, Pico puts it among the books falsely attributed to great authors: the “books of Plato on the cow” that the magicians pass around, full of “execrable dreams and inventions” (libros Platonis de uacca [...] execrabilibus somniis figmentisque refertos; Opera omnia, Basel, 1557, p. 419, Internet Archive; our translation).

The late Middle Ages credited the feat to one particular physician. The Castilian theologian Alonso de Madrigal, known as El Tostado (1400-1455), tells how Arnau de Vilanova (Arnald of Villanova) created an artificial human being in a vessel and did not dare to finish it, for fear of being taken for a usurper of God’s power (Arnau DB, “El mito de Arnau de Vilanova”). It is legend, and the database of the Universitat Autònoma de Barcelona presents it as such; see Arnau de Vilanova.

Three homunculi in the writings of Paracelsus

The Paracelsian corpus contains not one homunculus but several. Amadeo Murase, building on a finding by William R. Newman, sums it up as follows: besides the alchemical homunculus of De natura rerum, a pseudo-Paracelsian text, there is another in De homunculis et monstris and a third, “golem-like”, in Vom langen Leben and in the Liber de imaginibus; the alchemical version soon prevailed, although at first the other was almost as popular among the Paracelsians (Murase, Ambix 67, 2020, pp. 47-61, DOI; abstract on OpenAlex).

The wax homunculus. In Vom langen Leben (“On Long Life”, about 1526-1527 according to Sudhoff), which the Theatrum Paracelsicum classes among the authentic works (De longa vita record), Paracelsus discusses how to protect a long life against spells and proposes diverting the harm onto a figure:

ich mach ein homunculum ex cera [...], leg das an sein ort. nun also alles das, so wider mich incantativisch gebraucht wird, wird verbracht in dem bilt

“I make a homunculus of wax [...] and put it in its place. So everything that is used against me by incantation is carried off into the image.”

(Sudhoff, Sämtliche Werke, I. Abt., vol. 3, 1930, p. 243; Huser, vol. 6, p. 135; text transcribed from the scan, Internet Archive; our translation.) We leave out two words on which the copies disagree. This homunculus is not born of anything: it is a wax image, a device of image magic, related to the Liber de imaginibus, whose chapter 12 shares themes and vocabulary with Vom langen Leben (Theatrum Paracelsicum, Liber de imaginibus).

The homunculus of the horse’s belly, in passing. In the Latin De vita longa (1526-1527), which Huser published as a translation by Johannes Oporinus and the Theatrum Paracelsicum classes among the authentic works (De vita longa record), the author mentions the homunculus while discussing the quintessence of pearls, and refuses to dwell on it:

homunculus, quem necromantici alreonam, philosophi naturales mandragoram falso appellant [...]. origo quidem spermatis est; per maximam enim digestionem, quae in ventre equino fit, generatur homunculus

“The homunculus, which the necromancers call alreona and the natural philosophers, wrongly, mandrake [...]. Its origin is the sperm, for it is begotten by a very great digestion, which takes place in the horse’s belly.”

(De vita longa, book III, ch. 4, in Sudhoff, vol. 3, p. 274; Huser, vol. 6, p. 176; our translation.) Sudhoff’s apparatus for this passage records variants from the first edition of 1560, prepared by Adam von Bodenstein, so the passage was already in print twelve years before De natura rerum. The text adds that the homunculus resembles in every way the person it comes from, and stops there: “we shall pass over its virtues here”. There are no instructions, no timings, no feeding.

The homunculus of the monsters. De homunculis, a fragment of the Philosophia magna first printed in extract in 1567, is also listed among the authentic works in the Theatrum Paracelsicum (De homunculis record). According to Sudhoff, it deals with monsters born of unnatural mixtures (introduction to vol. 14, Internet Archive). It is the second of the three kinds of homunculus that Murase distinguishes.

The homunculus recipe: De natura rerum, book I

The famous homunculus recipe comes from book I of De natura rerum, “on the generation of natural things” (Sudhoff, vol. 11, 1928, pp. 316-317, Internet Archive). The text asks whether it is possible, by art and by nature, for a human being to be born outside a woman’s body, and answers yes: a man’s sperm is sealed in a cucurbit (a gourd-shaped flask) and left to putrefy for forty days in venter equinus, the steady heat of horse dung, until it moves and looks like a transparent human being; it is then fed for forty weeks on the “arcanum of human blood”, and the result is a complete child, only much smaller. “This we call a homunculus.” The text adds that these homunculi, once grown, turn into giants, dwarfs and other prodigious beings who know hidden things. The page Paracelsus and the pseudo-Paracelsus transcribes and translates the passage.

What is disputed is the authorship. De natura rerum consists of nine books and a preface dedicated to one Johann Winckelsteiner and dated at Villach in 1537; books I to VII were first printed in 1572, in the Metamorphosis prepared by Adam von Bodenstein (VD16 P 694, according to the Theatrum Paracelsicum). Karl Sudhoff, who edited it in 1928, already distrusted that date: Paracelsus usually gave the month and day, there is no record that he went back to Villach before 1538, and searches for Winckelsteiner in Fribourg (Switzerland) had found nothing. His conclusion was that the work, in its surviving form, did not come from Paracelsus’s pen (vol. 11, preface, pp. XXXI-XXXIII, Internet Archive). Urs Leo Gantenbein, who identified a manuscript of 1571 as the earliest source, concludes that at least three authors had a hand in it, that some parts are definitely forgeries and that only the books on death, resuscitation and the signature of natural things are very probably by Paracelsus; book I, the one with the homunculus, is not among them (abstract of his article in Ambix 67, 2020, pp. 4-29, DOI). Hiro Hirai notes that the work appeared just as the production of Paracelsian forgeries was reaching its peak (abstract of his article in Early Science and Medicine 24, 2019, DOI). The “1537” repeated on so many pages is the date of a dedication, not of a book.

Sudhoff did, however, put forward a conjecture: that Paracelsus, tired of a dry tone, might have written such a preface and the text after it as a joke around 1526-1527, “including the homunculus mockery” (einschließlich des Homunkulus-Spottes), and that others later reworked them (vol. 11, p. XXXIII; our translation). It is his hypothesis, not a fact.

To put the pieces together: in 1560 the passing mention of the homunculus begotten in the horse’s belly appears in print, in a text accepted as authentic; in 1572 the full recipe, with timings, feeding and the name, appears in another text, which scholars do not attribute to Paracelsus. We do not know whether the second built on the first, and we do not claim it did; what we do know is that the motif did not come out of nowhere.

The texts: authorship, dates and editions

Authorship and dates:

Editions and digital copies:

The Sudhoff scans on Internet Archive carry a warning that they may still be in copyright (InC 1.0), so we quote only short phrases, transcribed and translated by us.

From the alembic to the sperm cell: Hartsoeker and preformationism

At the end of the 17th century the word crossed from alchemy into the study of generation. In 1694 Nicolaas Hartsoeker describes the semen of men and of quadrupeds as full of tadpole-shaped “animals” and proposes that each “little animal” in the semen hides in miniature a complete animal of its kind, which joins the egg and grows inside it; if we could see through its skin, he writes, “we would perhaps see it as this figure shows it”, and he draws a child curled up inside the head of the sperm cell (Essay de dioptrique, Paris, 1694, arts. 88-89, pp. 227-230; the figure is on p. 230 of the Wellcome Library copy; our translation). That drawing is reproduced today as “Hartsoeker’s homunculus”, but Hartsoeker does not use the word, and he presents the figure as a conjecture (“peut-être”). It shows not a manufactured being but natural generation as preformationism understood it.

The homunculus in Goethe’s Faust

The version that has travelled furthest is a literary one, Goethe’s. In Act II of Faust, Part Two, in the “Laboratorium” scene, Wagner, Faust’s former assistant, is about to finish an experiment when Mephistopheles comes in, and Wagner announces: “Es wird ein Mensch gemacht”, “A man is being made” (our translation). Wagner scorns natural generation and holds that it is enough to “compose” human matter by mixing hundreds of substances, seal it in a flask and distil it; a little man appears in the flask, talks, and greets his “little father”. The Homunculus explains why he cannot leave the glass:

Natürlichem genügt das Weltall kaum,
Was künstlich ist, verlangt geschloßnen Raum.

“For what is natural the universe is scarcely enough; / what is artificial demands an enclosed space.”

(Goethe, Faust. Der Tragödie zweiter Teil, Act II, “Laboratorium”, text on Project Gutenberg; our translation.) The Homunculus guides Faust and Mephistopheles to the Classical Walpurgis Night, in Greece, and finally shatters against Galatea’s shell throne in the sea. The table of contents of the first edition gives the second part as finished in the summer of 1831, but Goethe did not want to publish it in his lifetime: he kept the manuscript in a cupboard in his study, and he had already arranged for Eckermann to publish it after his death, which came in March 1832 (Petra Lutz, “Faust II im Pappelholzschrank”, Klassik Stiftung Weimar, 2025). It was printed that same year as volume 41 of the Ausgabe letzter Hand, the edition “of the last hand” (Cotta; scan on Wikisource). The name of Paracelsus does not appear in the scene, and here we do not go into what Goethe read about homunculi. What the text does show is an echo of the 16th-century recipe: a human being made in a sealed vessel, without a mother, by a scholar’s hand.

Penfield’s homunculus in neurology, which is something else

In neurology the word refers to “Penfield’s homunculus”, motor or sensory: the figure of a little man with distorted proportions that shows how much of the surface of the cerebral cortex is devoted to each part of the body. It comes from the work of the neurosurgeon Wilder Penfield, who in 1937, with Edwin Boldrey, published the electrical stimulation study in Brain in which it appears (Brain 60, 1937, pp. 389-443); for its history and limitations, see G. D. Schott (Journal of Neurology, Neurosurgery and Psychiatry 56, 1993, pp. 329-333). All it shares with the alchemical homunculus is the Latin name: it is a map, not a creature, and there is no textual link between the two.

Homunculus myths, and where they come from

• “Paracelsus created a homunculus in 1537.” There is no record of any experiment: what exists is a text, and the recipe is in a book printed in 1572 that scholars do not consider his; 1537 is the date of its dedication.
• “The Russian homunculus in the video is real.” In the viral video a YouTube user, “Koney”, injects what he says is his semen into the yolk of a hen’s egg and keeps it warm for forty days. Chilango reported it on 7 June 2016, warning that there is no scientific evidence that a homunculus can be created and that what comes out is not, strictly speaking, a little man. Nor is it the alchemical recipe, which has no egg in it: just sperm in a cucurbit, later fed on the “arcanum of human blood”.
• “Paracelsus never spoke of homunculi.” That is not true either: in Vom langen Leben he speaks of a wax homunculus, and in De vita longa he mentions in passing the homunculus begotten in the horse’s belly.
• “Zosimos describes how to make a homunculus.” He describes a little man who appears in a dream; nobody makes him and there is no recipe.
• “The homunculus is ancient mythology.” The technical sense of the word dates from the 16th century, and the oldest precedent Newman points to, the Liber vaccae, is an Arabic book of magic of the 9th-10th centuries.
• “Hartsoeker saw a homunculus under the microscope.” He drew what might perhaps be seen, and said so.
• “It is a Hermetic symbol.” It does not appear in the Corpus Hermeticum or in the Emerald Tablet. Its link with Hermeticism runs through two channels. One is the posthumous fame of Paracelsus: the German edition of 1603 of the Apocalypsis Hermetis, a text he did not write, is the first to call him “Hermes Secundus” (Theatrum Paracelsicum). The other is alchemy in general, a neighbour of Hermeticism but not the same thing (see Hermeticism and its neighbours).

Recent fiction plays with the idea too: in the British comedy Small Prophets, by Mackenzie Crook, which premiered on the BBC in 2026 and has been on Apple TV since 7 October 2026, a man tries to raise homunculi that predict the future, using an old recipe of rainwater, horse dung and alchemy (Apple press release, 28 August 2026).

How to read the homunculus story

Read it in three layers, in this order. The fact: an Arabic book of magic; in Paracelsus, a wax homunculus, a mention of the horse’s belly and a treatise on homunculi and monsters; and, in a text known since 1571-1572 and printed under his name, the full recipe. The debate: who wrote De natura rerum, whether the Liber de imaginibus is by Paracelsus, and how much the homunculus owes to the Liber vaccae. The reception: Hartsoeker’s drawing, Wagner’s flask, the viral videos and the TV series and, unrelated to all of these, Penfield’s map. The homunculus belongs to an old question in alchemy, whether art can equal nature, which also comes up in the Great Work.

Further reading

• The scene in English: Goethe, Faust, translated by Bayard Taylor, Second Part, Act II, scene II, “Laboratory” (Wikisource).
• Hartsoeker’s figure (1694), on p. 230 of the Wellcome Library copy, in the public domain.
• Who wrote what in the corpus of Paracelsus: the page Paracelsus and the pseudo-Paracelsus, with a table of the most cited works and their authorship.

Key facts

Name	Homunculus, from the Latin homunculus, “little man”, a diminutive of homo
What it is	A tiny human being made by art, without a mother, from semen
Recipe	De natura rerum, book I (Sudhoff I/11, pp. 316-317); dedication dated 1537, first printed in 1572; not by Paracelsus in its surviving form according to Sudhoff (1928), and outside the probably authentic parts according to Gantenbein (2020)
Authentic Paracelsus	Wax homunculus in Vom langen Leben (about 1526); mention of the homunculus “in ventre equino” in De vita longa (printed 1560); De homunculis
Technical forerunner	Kitāb al-nawāmīs or Liber vaccae, Arabic and pseudo-Platonic, written between the mid-9th and the early 10th century; the oldest Latin manuscript dates from the late 12th or early 13th century
Literary reception	Goethe, Faust II, Act II, scene “Laboratorium” (published 1832)
Not to be confused with	The cortical homunculus of Penfield and Boldrey (1937)

Fair questions

What is a homunculus in alchemy?

A tiny artificial human: according to a text attributed to Paracelsus, it could be made from human semen sealed in a vessel, kept warm in horse dung for forty days and then fed on the “arcanum of human blood”. The word is Latin for “little man”, a diminutive of homo. It is not a creature of ancient mythology: the technical sense was fixed in the 16th century.

How is a homunculus made, according to the recipe?

The recipe in De natura rerum, book I, says to seal sperm in a cucurbit, let it putrefy for forty days in horse dung until it “moves”, and feed it for forty weeks on the “arcanum of human blood”. It is a 16th-century text, known since 1571-1572, not an account of a tested experiment: there is no documented case of anyone succeeding.

Did Paracelsus create a homunculus?

There is no evidence of any such experiment by him. The famous recipe is in a book printed in 1572, thirty-one years after his death, which Karl Sudhoff no longer considered his work and which Urs Leo Gantenbein (2020) places outside the parts that are probably authentic. In writings accepted as authentic, Paracelsus describes a wax homunculus used against spells and mentions in passing the homunculus begotten in the horse’s belly, without giving a recipe.

Is the “Russian homunculus” video real?

There is no evidence that it is. In the video, a YouTube user injects what he says is his semen into a hen’s egg and keeps it warm for forty days; when it reported the video in June 2016, the website Chilango warned that there is no scientific evidence that a homunculus can be created. Nor does it follow the alchemical recipe, which uses no egg.

What is the homunculus in Goethe’s Faust?

A little man whom Wagner, Faust’s former assistant, creates in a flask in the “Laboratorium” scene of Act II of Part Two, published in 1832. He talks as soon as he is born, cannot leave the glass, guides Faust to the Classical Walpurgis Night and finally shatters against Galatea’s shell throne in the sea. In Bayard Taylor’s English translation the scene is headed “Laboratory”.

What does it have to do with Penfield’s homunculus?

Only the name. Penfield’s homunculus is a drawing of a distorted human figure that shows how much of the cerebral cortex is devoted to each part of the body; it comes from the studies by Wilder Penfield and Edwin Boldrey published in 1937. It is a neurological map, not an alchemical creature.

Sources & further reading

• Karl Sudhoff (ed.), Theophrast von Hohenheim gen. Paracelsus, Sämtliche Werke, I. Abteilung, 14 vols. (1922-1933): vol. 3 (1930), Vom langen Leben, pp. 221-245 (the wax homunculus passage, p. 243), De vita longa, pp. 247-292 (book III, ch. 4, p. 274) and German fragments, pp. 293-308, Internet Archive; vol. 11 (1928), Sudhoff’s preface (dated July 1926), pp. XXXI-XXXIII, and De natura rerum, pp. 307-403, Internet Archive; vol. 14 (1933), De homunculis, pp. 325-336, Internet Archive; Wellcome Library copies (InC 1.0).
• Theatrum Paracelsicum, records: De natura rerum, Liber de imaginibus, De longa vita (Vom langen Leben), De vita longa, De homunculis and Apocalypsis Hermetis (accessed 30 and 31 October 2026).
• Amadeo Murase, “The Homunculus and the Paracelsian Liber de imaginibus”, Ambix 67, no. 1 (2020), pp. 47-61, DOI 10.1080/00026980.2020.1720359; abstract on OpenAlex.
• Urs Leo Gantenbein, “Real or Fake? New Light on the Paracelsian De natura rerum”, Ambix 67, no. 1 (2020), pp. 4-29, DOI 10.1080/00026980.2020.1720339; author’s abstract on OpenAlex.
• Hiro Hirai, “Into the Forger’s Library: The Genesis of De natura rerum in Publication History”, Early Science and Medicine 24 (2019), pp. 485-503, DOI 10.1163/15733823-02456p05; abstract on OpenAlex.
• Marcellin Berthelot and Charles-Émile Ruelle, Collection des anciens alchimistes grecs (Paris: Steinheil, 1887-1888), vols. II-III, Zosimos, “Sur la vertu”, lesson I (translation, vol. III, pp. 117-119), Internet Archive (public domain).
• Maaike van der Lugt, “‘Abominable mixtures’: the Liber vaccae in the medieval West, or the dangers and attractions of natural magic”, Traditio 64 (2009), pp. 229-277, DOI 10.1017/S0362152900002312; the opening of the article and the notes cited (2, 3, 9, 12, 15, 46, 67, 99 and 133) can be read on Cambridge Core.
• Giovanni Pico della Mirandola, Disputationes adversus astrologiam divinatricem, book I, in Opera omnia (Basel: Heinrich Petri, 1557), p. 419, Internet Archive, copy of the Biblioteca Nazionale Centrale di Roma (Public Domain Mark).
• William R. Newman, Promethean Ambitions: Alchemy and the Quest to Perfect Nature (Chicago: University of Chicago Press, 2004), ch. 4, “Artificial Life and the Homunculus”, publisher’s page.
• Mary Baine Campbell, “Artificial Men: Alchemy, Transubstantiation, and the Homunculus”, Republics of Letters 1, no. 2 (2010), Stanford.
• Arnau DB (Universitat Autònoma de Barcelona), “El mito de Arnau de Vilanova”, webs.uab.cat/arnau (accessed 30 October 2026).
• Nicolaas Hartsoeker, Essay de dioptrique (Paris, 1694), arts. 88-91, pp. 227-230 (the figure, p. 230), Internet Archive, Wellcome Library copy (Public Domain Mark).
• Johann Wolfgang von Goethe, Faust. Der Tragödie zweiter Teil (1832), Act II, “Laboratorium”, text on Project Gutenberg, no. 2230 (public domain); first edition: Goethe’s Werke. Vollständige Ausgabe letzter Hand, vol. 41 (Stuttgart and Tübingen: Cotta, 1832), title page and contents (“Vollendet im Sommer 1831”) in the Wikisource scan. Petra Lutz, “Faust II im Pappelholzschrank”, Klassisch modern (Klassik Stiftung Weimar), 2025, pp. 8-13, PDF (copy on Internet Archive). In English: Faust, tr. Bayard Taylor, Second Part, Act II, scene II, “Laboratory”, Wikisource.
• Wilder Penfield and Edwin Boldrey, “Somatic motor and sensory representation in the cerebral cortex of man as studied by electrical stimulation”, Brain 60 (1937), pp. 389-443, DOI 10.1093/brain/60.4.389; G. D. Schott, “Penfield’s homunculus: a note on cerebral cartography”, Journal of Neurology, Neurosurgery and Psychiatry 56 (1993), pp. 329-333, DOI 10.1136/jnnp.56.4.329.
• Charlton T. Lewis and Charles Short, A Latin Dictionary (Oxford: Clarendon Press, 1879), s.v. “homunculus”, p. 860, Internet Archive.
• Chilango, “VIDEO: ruso crea una extraña criatura con su semen”, 7 June 2016, chilango.com.
• Apple TV, “Apple TV to premiere season one of captivating comedy ‘Small Prophets’ on Wednesday, October 7”, press release, 28 August 2026, apple.com.