Hyma

hyma (αἷμα), means life essense, which can mean either blood, or semen. That which sustains life, or causes life.

• Introduction
• Hippocratic medicine — hyma (αἷμα) as zoutikon (ζωτικόν)
• Aristotle — hyma (αἷμα) and sperma (σπέρμα) are materially linked
  • Aristotle, Generation of Animals (Γενέσεως Ζῴων)
• Galenic medicine — hyma (αἷμα) as zoutikon (ζωτικὸν) pneuma (πνεῦμα) carrier
• Tragic & ritual Greek — αἷμα as life itself
• Epiphanius Panarion
• Sources - Galen Deep Dive
  • Galen: blood and semen are the same life-substance, differently refined
  • Semen is generated from blood by alteration
  • Blood visibly becomes semen in the vessels
  • Semen = most refined, useful blood-product
• Sources - Aristotle Deep Dive
  • sperma (σπέρμα) is the final refinement of nourishment
  • sperma (σπέρμα) is a residue specifically of blood
  • sperma (σπέρμα) is “cooked,” but not fully formed flesh
  • sperma (σπέρμα) has great dynamis (δύναμις) (power), not mass
  • sperma (σπέρμα) is a whole animal in potentiality
  • sperma (σπέρμα) works by generative motion, not by bulk
  • sperma (σπέρμα) explains resemblance between parent and offspring
• Conclusion

Introduction

in Greek usage hyma (αἷμα) is not merely “blood” as a mechanical fluid, but a vital substrate—the bearer of life-force, heat, lineage, and generative capacity. It's well attested in classical medical, philosophical, and ritual Greek.

LSJ explicitly frames hyma (αἷμα) as more than a substance, a vital principle.

Hippocratic medicine — hyma (αἷμα) as zoutikon (ζωτικόν)

In the Hippocratic Corpus, hyma (αἷμα) is one of the four humors, but it is consistently:

• warm
• moist
• life-supporting

Blood loss = loss of life because hyma (αἷμα) carries vitality, not merely oxygen (a modern abstraction).

Aristotle — hyma (αἷμα) and sperma (σπέρμα) are materially linked

This is the strongest support for hyma == semen (a refinement of blood).

Aristotle, Generation of Animals (Γενέσεως Ζῴων)

Aristotle explicitly teaches that:

• sperma (σπέρμα) - semen is a refinement of blood
• Blood is the material cause of generation
• Semen is blood worked upon by heat

Thus:

• hyma (αἷμα) → sperma (σπέρμα) → animated life force (ζωή)
• Semen is blood transformed, not a separate category

So when Greek authors speak of αἷμα as life-bearing, they are not excluding semen—they are placing semen within the blood-life continuum.

Galenic medicine — hyma (αἷμα) as zoutikon (ζωτικὸν) pneuma (πνεῦμα) carrier

Galen explicitly treats αἷμα (blood) and σπέρμα / γονή (semen) as the same underlying ζωτική substance in different states.

Unlike Hippocrates (implicit) and Aristotle (systematic but cautious), Galen makes this identification overt and medical.

Galen refines hyma (αἷμα) as zoutikon (ζωτικὸν) pneuma (πνεῦμα) carrier, further:

• Blood carries pneuma (πνεῦμα) (vital spirit)
• Different refinements of blood correspond to:
  • nourishment
  • vitality
  • generation

Blood is not inert; it is animated matter.

Again: blood = life-essence, with semen as a specialized expression.

Tragic & ritual Greek — αἷμα as life itself

In tragedy and cultic language:

• hyma (αἷμα) = life forfeited
• spilling blood = releasing life
• hyma (αἷμα) cries out, pollutes, binds oaths

Examples:

• Aeschylus, Sophocles: hyma (αἷμα) is what binds kin, curses houses, awakens Erinyes
• Sacrifice: blood is offered because it contains Zoe (ζωή - animated life force), not because it is red fluid

This is why:

• blood libations matter
• kinship is hyma (αἷμα)
• murder is hymatochusia (αἱματοχυσία) — life-pouring

Epiphanius Panarion

While writers often distinguish hyma (αἷμα) and sperma (σπέρμα) terminologically, late antique sources attest that semen could be explicitly called hyma (αἷμα) when understood as a flowing, ingestible life-substance. Epiphanius (Panarion 26) reports groups who themselves designate sexual emission as “hyma” and treat it as nourishment of life, demonstrating that hyma (αἷμα) could denote semen, as that life-essence.

• Epiphanius Panarion

Sources - Galen Deep Dive

In the following Galen sources, the identification of αἷμα (blood) and σπέρμα / γονή (semen) as manifestations of a single life-bearing substance is made explicit and unambiguous. In De Semine, Galen states directly that semen is generated from blood, specifically from its purest and most fully concocted portion, differing not in nature but only in degree of refinement and in dynamis (δύναμις). Semen is therefore not a separate essence but blood further processed by heat and pneuma for generative purposes. This identity is reinforced physiologically in De Usu Partium, where Galen observes that the loss of semen weakens the body in the same way as the loss of blood—because both are losses of the same zoutike (ζωτική) stock. Across these works, Galen treats blood as the primary life substance sustaining the organism, and semen as that same substance redirected toward generation. Thus, in Galen’s medical system, what you are calling hyma is unequivocally a general life essence, which appears as blood in nourishment and as semen in reproduction, distinguished by function and refinement rather than by substance.

Galen: blood and semen are the same life-substance, differently refined

Galen repeatedly states that semen is produced from blood, and more specifically from the purest, most concocted (πεπεμμένον) portion of blood. For Galen, blood is the primary ζωτική substance formed in the liver; semen is that same substance further refined by heat and pneuma for generative purposes. This is not metaphorical: Galen is explicit that semen is blood transformed, not a different essence.

• see De Semine at Perseus Scaife Viewer

Semen is generated from blood by alteration

Blood visibly becomes semen in the vessels

Semen = most refined, useful blood-product

Sources - Aristotle Deep Dive

In Aristotle’s biology, hyma (αἷμα) is not merely “blood” in a modern anatomical sense; it functions as the primary life-bearing substrate of the organism — what is called "life essence". Semen/sperma (σπέρμα) is not a different essence, but the same hyma (αἷμα) redirected in function. Aristotle never introduces a second vital substance for generation. Instead, he insists on one underlying zoutike (ζωτική) hule (ὕλη) that appears under different names depending on context, role, and degree of processing. Thus, when Aristotle (or later writers operating in this framework) speaks of the life-bearing substance without specification, context alone determines whether hyma (αἷμα) is meant as blood-in-the-body e.g. body hyma, or blood-as-sperma (σπέρμα), e.g., generative hyma.

Across these seven passages, Aristotle shows that hyma (αἷμα) is the single life-bearing essence (ζωτική ὕλη) from which both bodily life and generative power proceed. Blood is hyma (αἷμα) as nourishment fully actualized into the body, distributed to the parts and sustaining their activity; semen is the same hyma (αἷμα), but withheld at the final stage of nourishment, refined, altered, and intentionally left incomplete so that it does not become flesh. Because sperma (σπέρμα) is this life essence held in reserve, it contains the whole organism in potentiality, carrying formative motion rather than bulk matter. Its dynamis (δύναμις) derives precisely from being the purest remainder of hyma (αἷμα), which explains both its generative efficacy and the bodily weakening caused by its loss. There is therefore no ontological split between blood and semen: they are one life essence under two functions — hyma (αἷμα) as body when actualized, hyma (αἷμα) as sperma (σπέρμα) when redirected toward generation. Consequently, when Aristotle (or writers using his physiological grammar) speaks of hyma (αἷμα) without qualification, only context determines whether the life essence is being named as blood or as semen, not a change in substance but a change in role.

sperma (σπέρμα) is the final refinement of nourishment

Aristotle situates sperma (σπέρμα) at the very end of the nutritive chain: it is not generic waste, but what remains after nourishment has reached its highest bodily form (blood).

• trophe (τροφή)
  • belongs to the nutritive soul (threpitike/θρεπτικὴ psuche/ψυχή), the most basic life-function shared by all living things
  • that by which a living thing is maintained in being, through assimilation into its own substance.

• γονή - semen as a biological event (the act and product of generation).
  • What is released, when, and from where, such that generation can begin?
• σπέρμα - semen as an explanatory principle (the source of form and motion).
  • What causes this matter to become this kind of living thing?
• περίττωμά = residue
• τροφῆς καὶ τῆς ἐσχάτης = of nourishment, specifically final nourishment (blood)

sperma (σπέρμα) is a residue specifically of blood

Here Aristotle closes the logical chain: because blood is the final nourishment, semen must be a residue of blood itself.

sperma (σπέρμα) is “cooked,” but not fully formed flesh

Aristotle distinguishes semen from blood by degree of digestion (pepsis/πέψις): semen (σπέρμα) is altered, but intentionally unfinished.

sperma (σπέρμα) has great dynamis (δύναμις) (power), not mass

Because semen is the purest remainder of blood, its loss weakens the body; its efficacy lies in its potency, not its size.

sperma (σπέρμα) is a whole animal in potentiality

Aristotle states this with extreme clarity: semen is not a part, but the entire organism implicitly, held in δύναμις.

sperma (σπέρμα) works by generative motion, not by bulk

Here Aristotle explicitly doubts that the physical body of semen is the cause at all; instead, the cause is an internal principle of motion.

sperma (σπέρμα) explains resemblance between parent and offspring

Because semen derives from the same blood that formed the parent’s body, likeness is not accidental but necessary.

In Generation of Animals II.3, Aristotle then confirms that the same life-bearing substance underlies blood, semen, menstrual matter, and the embryo. He explicitly states that semen and embryos are alive, possessing the nutritive soul in potentiality, which shows that semen is not inert material but already ζωτικόν. He further explains that semen acts not by becoming bodily matter but by carrying an internal principle of motion—heat and pneuma—that organizes the female residue, which is itself also a residue of nourishment and is even called “semen,” though “not pure,” because it lacks the formative principle. Throughout the chapter, life is treated as a continuous process unfolding from one substrate, with differences between blood, semen, and menstrual matter arising from function, motion, and degree of activation rather than from distinct substances. In this way, Book II.3 reinforces—without expanding—the conclusion already secured in I.18: what Aristotle is calling hyma is a general life essence, not blood alone, and semen is simply that same essence operating in a generative mode.

According to Aristotle, Hyma can be either blood or semen.

• see Generation of Animals I.18
• see Generation of Animals II.3

Conclusion

In Greek thought:

• hyma (αἷμα) = zouophoron (ζωοφόρον) hupostrouma (ὑπόστρωμα) life-bearing substrate
• It can appear as:
  • circulating blood
  • generative semen or ejaculate (sperma (σπέρμα))
  • lineage / kinship
  • sacrificial vitality

hyma (αἷμα) is the vital substance that sustains and transmits life; it appears as blood in circulation and as semen in generation, differentiated by heat and function, not by essence.

• Blood and semen are not different kinds of stuff
• They are the same underlying substance

They belong to the same ontological category.

That is a fully classical definition (not modern).