+++
title = "The Rain Over Helicon"
description = "M. L. West traced Greek myth eastward. A rigorous audit of Hesiod, Homer, Gilgamesh, divine combat, poetic craft, and the limits of borrowing in the Aegean."
template = "articles-page.html"
date = 2026-08-30
draft = false

[extra]
claim_type = "speculative"
editorial_pass = "2026-05"
article_type = "explainer"
category = "Comparative Mythology"
author = "Zara Zinsfuss"
author_slug = "zara-zinsfuss"
core_claim_ids = ["woh-claim-0004", "woh-claim-0005", "woh-claim-0007"]
core_versions = { woh-claim-0004 = "0.2.0", woh-claim-0005 = "0.2.0", woh-claim-0007 = "0.1.0" }
summary = "The third article in the Odyssey sequence turns from excavation and transmission to method. M. L. West's *The East Face of Helicon* does not rest on one sensational parallel: it accumulates evidence across Hesiod and the Kumarbi cycle, the Odyssey and Gilgamesh, divine combat, poetic procedure, formulaic diction, and the human routes connecting the Aegean to Anatolia and the Levant. This Explainer grades that evidence, preserves Greek invention and Indo-European inheritance, and marks the exact boundary between documented literary dependence and Wheel of Heaven's speculative shared-referent reading."
keywords = ["M. L. West", "East Face of Helicon", "Greek mythology", "Odyssey", "Gilgamesh", "Hesiod", "Kumarbi", "Typhoeus", "Near East", "poetic transmission", "comparative mythology"]
references = [
    # The Wheel of Heaven canon
    { id = "the-book-which-tells-the-truth", locator = "Chapter 5, paragraph 54 (Greece among the creator-base regions, where mythology contains testimonies)" },

    # Ancient primary texts
    { id = "theogony-and-works-and-days", locator = "Theogony 154–182 (Ouranos and Kronos), 453–467 (Kronos and Zeus), 617–720 (Titanomachy), 820–868 (Typhoeus)" },
    { id = "hittite-myths", locator = "The Song of Kumarbi, Song of Ullikummi, and Illuyanka tales" },
    { id = "enuma-elish", locator = "Tablets I and IV–V (divine succession and Marduk against Tiamat)" },
    { id = "the-ugaritic-baal-cycle-volume-i", locator = "KTU 1.1–1.2 (Baal against Yamm); KTU 1.5 i 1–3 (Lotan)" },
    { id = "odyssey-greek-text", locator = "1.1–5 (proem); Books 10–12 (Circe, the dead, wakefulness, and the cattle of Helios); Books 5–8 (Calypso and the Phaeacians)" },
    { id = "epic-of-gilgamesh", locator = "Standard Babylonian Tablet I proem and Tablets IX–XI as discussed by West; the corpus's own translation covers Tablet XI" },

    # Comparative scholarship and oral poetics
    { id = "the-east-face-of-helicon-west-asiatic-elements-in-greek-poetry-and-myth", locator = "Preface vii–ix; ch. 1 pp. 59–60; ch. 4 pp. 168–174, 190–191; ch. 5 pp. 220–226; ch. 6 pp. 276–304, 332; ch. 8 pp. 402–417, 437; ch. 12 pp. 586–630, read for this article and short quotations checked against page images" },
    { id = "the-orientalizing-revolution-near-eastern-influence-on-greek-culture-in-the-earl", locator = "The eighth- and seventh-century movement of Near Eastern specialists and practices into Greek communities" },
    { id = "from-hittite-to-homer-the-anatolian-background-of-ancient-greek-epic", locator = "Anatolian festival epic and its transmission into Aegean poetic traditions" },
    { id = "homer-s-odyssey-and-the-near-east", locator = "Book-length treatment of the Odyssey's Near Eastern comparanda" },
    { id = "travelling-heroes-greeks-and-their-myths-in-the-epic-age-of-homer", locator = "Euboean and Levantine contact geography" },
    { id = "the-singer-of-tales", locator = "Oral-formulaic composition and the recomposition of epic in performance" },
    { id = "indo-european-poetry-and-myth", locator = "The Indo-European inheritance that remains one strand of Greek poetic and mythological formation" },

    # Critical controls
    { id = "the-structural-study-of-myth-journal-of-american-folklore-68-the-mytheme-the-riv", locator = "The structural alternative: recurring mythic relations need not preserve an event" },
    { id = "is-god-a-space-alien-the-cosmology-of-the-ra-lian-church", locator = "The category-substitution objection to technological readings of religion" },
    { id = "aliens-adored", locator = "Academic history and context for Raëlian interpretation" }
]

footnotes = [
    { content = "West's subtitle says 'West Asiatic,' and his principal field is Mesopotamia, Anatolia, Syria-Phoenicia, and the routes joining them to the Aegean. Egypt belongs to the wider contact world but is not the centre of this book's argument. This article therefore uses 'Near Eastern' and 'eastern Mediterranean' more often than the looser word 'East.'" },
    { content = "The quotations from West in this article are deliberately few and short. The relevant chapters were read from a complete local research copy; extracted text was used only to locate passages, and the retained wording was checked against rendered page images. Page numbers refer to the printed 1997 book." },
    { content = "The Standard Babylonian Epic of Gilgamesh is not a single-stage composition. It reorganises and extends older Akkadian and Sumerian materials. 'Older than Homer' therefore describes the attested narrative tradition, not a pristine authorial original or a simple line from one tablet to one Greek poet." },
    { content = "The final interpretive section binds three separate research records. Claim 0005 carries the mainstream transmission case at direct strength. Claim 0004 carries the Greek theomachy reading at speculative strength. Claim 0007 carries the wider Greece-in-the-Elohimian-sphere thesis at framework strength. Their alternatives and revision triggers remain part of the article's evidential apparatus." }
]
+++

Rain was M. L. West's answer to the last refuge of cultural isolation. A
classicist could concede an eastern parallel and then point to everything
Greek that did not match it: another name, another motive, another ending,
another theology. West's reply, in the preface to *The East Face of Helicon*,
was that differences no more cancel a pattern of influence than a roof
cancels the weather falling beyond it. The question is not whether Greece
made the material its own. Of course it did. The question is how much rain
fell, from which direction, and what grew after it reached Greek ground.

This is the third article in a sequence. [*The World Behind the
Odyssey*](/articles/the-world-behind-the-odyssey/) excavated the oral and
Bronze Age strata beneath Homer. [*The East Face of
Homer*](/articles/the-east-face-of-homer/) followed one trench toward
Mesopotamia and asked what literary borrowing can prove. The present article
audits the instrument used in both excavations. West's case is often reduced
to two arresting comparisons — Hesiod with the Hurrian *Song of Kumarbi*,
Homer with *Gilgamesh* — or to a slogan in which Greece simply copied the
East. Neither reduction does justice to the book.

West argues by accumulation. A bizarre sequence in a divine genealogy carries
more weight than a generic serpent fight. A cluster of narrative scenes
carries more than an isolated motif. Repeated procedures, formulas, and
idioms can reinforce a plot comparison because influence has then entered the
workshop of poetry, not merely its store of stories. Chronology supplies a
direction; archaeology supplies occasions of contact. None of these pieces is
equally certain, and few reveal the exact traveller who carried a tale. Taken
together, they make archaic Greece visible inside an interconnected eastern
Mediterranean world.{{ footnote(id="1") }}

That method also sets a discipline for Wheel of Heaven. The documented
movement of stories must be stated before any deeper reading of those stories
begins. Transmission is evidence for transmission. It is not, by itself,
evidence that two traditions remember the same event.

## A dossier, not a master key

The weakest form of comparison places two myths side by side and declares
them related because both contain a flood, a dragon, or a quarrel among gods.
Human societies repeatedly imagine floods and monsters. Hierarchies generate
succession stories. Storms readily become combatants. Any global survey can
manufacture resemblance if its categories are broad enough.

West's stronger cases have a different shape. They combine several tests:

| Test | What raises the probability of transmission |
| --- | --- |
| **Articulation** | Several unusual actions occur in the same order, rather than one generic motif appearing in both texts |
| **Density** | Plot, scene, formula, and idiom point in the same direction |
| **Chronology** | The eastern witness is centuries older than the Greek one |
| **Contact** | Speakers, objects, scripts, and practices can be shown crossing the relevant corridor |
| **Transformation** | The Greek version is intelligible as active adaptation, including its departures from the eastern form |

This is why the book ranges so widely. Its chapters move from gods and cosmic
geography to poetic form, phraseology, proverbs, heroic narrative, wisdom,
and finally the historical channels by which the material could travel. The
argument does not require every proposed Semitic idiom or every shared simile
to be a loan. Some will be independent. The claim is that the high-confidence
cases establish a direction and the lower-level correspondences reveal how
deeply contact entered the poetic system.

The method admits Greek particularity from the start. West does not derive
the dactylic hexameter from an eastern verse form. He finds eastern
counterparts for poems that begin with a singer announcing a theme, but the
Muses who authorise Greek song remain Greek. Influence and invention occupy
the same poem.

## The safe launching pad: Hesiod and Kumarbi

West begins his sustained comparison with Hesiod because this is where the
case is least dependent on persuasion. The *Theogony* tells how Ouranos
suppresses his children; Kronos, armed by Gaia, castrates his father and takes
power; Kronos then swallows his own children to prevent succession; Zeus is
hidden, returns, and becomes the final divine king. The Hittite-language
*Song of Kumarbi*, preserving Hurrian tradition and attested centuries before
Hesiod, tells how Kumarbi overthrows Anu by biting off his genitals, receives
the previous god's offspring inside himself, and brings forth the storm god
Teshub, who becomes his victorious rival.

The correspondence is not merely “young god replaces old god.” West isolates
a chain of particulars:

1. Heaven is ruled by a succession of divine generations.
2. The middle ruler attacks his predecessor's genitals.
3. The assault transfers the next generation into the attacker's body.
4. The threatened ruler tries to prevent the birth or emergence of a rival.
5. A concealed or internalised younger generation returns.
6. A young storm god becomes the durable sovereign.
7. The displaced powers generate or recruit another challenger.
8. Even the extraordinary birth of a deity from the head may belong to the
   same field of tradition.

No single line proves dependence. The ordered accumulation, joined to eastern
priority, makes independent invention increasingly expensive. West also
compares the Babylonian *Enuma Elish*, where Anu, Ea, and Marduk form another
sequence of divine generations and the young storm-associated champion wins
cosmic kingship. The Babylonian resemblance is broader and less exact than
the Kumarbi sequence. The comparison gains credibility because West says so.
He grades his own witnesses instead of forcing them into equality.

Differences matter just as much. Kumarbi's body becomes a site of pregnancy;
Kronos deliberately swallows children already born. The stone Kronos receives
in place of Zeus has its own Greek ritual afterlife. Hesiod reorganises the
story around Gaia's counsel, Zeus's justice, and the stable order of Olympus.
The Greek poem is not a damaged Hittite tablet. It is a Greek theogony built
with inherited and received materials. At the chapter's end, West calls the
result “a truly extraordinary accumulation of oriental materials.”{{ footnote(id="2") }}

That is the strongest footing in the whole debate: dependence with
transformation. A useful argument about Near Eastern influence should begin
there, not with a list of gods whose names happen to sound alike.

## The combat family keeps its differences

After succession comes combat, and here the evidence becomes both richer and
easier to misuse. Hesiod's Zeus fights Typhoeus, a many-voiced serpentine
challenger born from Earth. Hittite and Hurrian traditions give the storm god
an enemy in the serpent Illuyanka and, in another cycle, the stone giant
Ullikummi. At Ugarit, Baal wins kingship through conflict with Yamm, the Sea,
and the tradition remembers the twisting serpent Lotan. In Babylon, Marduk
defeats the sea-monster Tiamat and makes an ordered cosmos from her body.

The temptation is to flatten these combats into one original story. West
does something more exact. He treats the Typhoeus episode as a relatively
self-contained combat narrative attached to the Greek succession sequence.
He then compares its features across several eastern families: the storm god,
the challenge to divine order, the serpentine or elemental adversary, the
temporary danger to the champion, the use of thunderous weapons, and the
establishment or defence of kingship.

Some relations are genealogical; others may be typological. Baal's struggle
with Yamm is a contest for sovereignty, but it is not Hesiod's battle scene in
translation. Ullikummi is stone, not a sea-serpent. Marduk constructs the
world from Tiamat's body; Zeus does nothing comparable with Typhoeus. The
family resemblance has historical force because names, formulas, cults, and
stories moved through connected Syrian, Anatolian, Mesopotamian, and Aegean
communities. It does not erase the theological work each tradition performed
with the pattern.

This distinction protects the comparison from two errors. The first is
minimalism: because no pair matches in every detail, no transmission occurred.
The second is the decoder ring: Typhoeus, Ullikummi, Lotan, and Tiamat must all
be masks for one named person or one precisely recoverable event. West's
philology supports neither extreme. It identifies a circulating repertoire
of divine conflict and follows its local recompositions.

## When technique travels with the story

Whole myths attract attention because their similarities are visible. West's
more consequential claim is that eastern influence reached the machinery by
which Greek poets made narratives.

Greek, Akkadian, Ugaritic, and Hebrew poems organise action through recurring
procedures: a grievance is announced; the gods assemble; a speaker proposes a
course; a messenger receives instructions, travels, arrives, repeats the
instructions, and returns; a feast or arming sequence unfolds through stable
steps. Long speeches occupy a striking share of the narrative. Extended
similes pause action to open a second field of experience. Characters carry
epithets; earth is dark or broad; hostile force weighs upon a people through
heavy hands.

None of those devices is individually exotic. Oral poets everywhere need
repeatable structures, and formulaic diction is a practical consequence of
composition in performance. West therefore argues
case by case. A commonplace epithet receives little weight. An unusual idiom
with a plausible Semitic construction receives more. A procedural sequence
that accompanies an already persuasive mythic relation becomes cumulative
support.

The result is subtler than the claim that Greeks borrowed stories. A story
can travel as a summary and be rebuilt entirely in local technique. West's
evidence suggests that eastern and Greek singers also shared habits of
opening, pacing, repeating, and dignifying narrative. Contact reached the
poetic workshop.

Yet the workshop remained Greek. The hexameter's structure, the economy of
the Homeric noun-epithet system, the invocation of the Muses, and the exact
architecture of the surviving epics cannot be debited to a Near Eastern
account. Oral-formulaic scholarship adds another independent history: the
Greek diction was built through generations of Greek performance. Eastern
material entered that living system and was naturalised inside it.

## The man who saw too much

The second famous case lies in West's chapter on the *Odyssey*. Its proem
asks the Muse to sing of a far-wandering man who saw the cities and learned
the minds of many people, suffered at sea, and struggled for return. The
Standard Babylonian *Gilgamesh* opens with a man whose knowledge comes from
seeing everything, uncovering what was hidden, and bringing back intelligence
from before the Flood.{{ footnote(id="3") }} The two beginnings introduce
heroes defined by travel, suffering, knowledge, and return from a boundary
ordinary people do not cross.

West does not rest on the proems. He follows a narrative strand:

- Odysseus is detained by Calypso and instructed by Circe; Gilgamesh meets
  Siduri at the edge of the world. Each hero's homeward or knowledge-seeking
  passage turns on a woman in a remote place.
- The Phaeacians receive a stranger who has crossed an impossible sea, cleanse
  and clothe him, entertain him, hear his story, and convey him toward home.
  Related hospitality and transition scenes surround Gilgamesh's movement at
  the world's margin.
- Both heroes enter the domain of the dead in pursuit of knowledge unavailable
  among the living.
- A test of wakefulness exposes the mortal body's limit.
- The slaughter of the cattle of Helios belongs beside a wider eastern field
  in which violation of a sacred bovine brings catastrophe, including the
  Bull of Heaven tradition.

The clustering leads West to an “especially strong and clear relationship”
between the *Odyssey*'s wanderings and *Gilgamesh*. He immediately enforces
the limit: “He is, then, no Gilgamesh.” Odysseus is calculating, restrained,
and fixed upon home; Gilgamesh is kingly, violent, grief-driven, and finally
confronted with mortality. The Greek poet places his hero in some inherited
settings and scenes without importing the Babylonian personality.

West adds one more qualification that summaries often lose. Except for this
wanderings material, he judges the *Odyssey* less densely filled with eastern
matter than the *Iliad*. Even inside the Homeric corpus, influence is uneven.
There is no reason to imagine a single act of copying or a deliberate division
in which one poet assigned eastern material to one epic and excluded it from
the other. Traditions absorb at different depths and at different times.

## How a story crosses a sea

Comparison establishes a relationship; history must make the relationship
possible. West's final chapter offers several windows rather than one route.

During the high Mycenaean period, Aegean palaces participated in a diplomatic
and commercial system reaching Anatolia, Cyprus, Syria, and Egypt. The palace
world's collapse around 1200 BCE destroyed administrations without emptying
the sea. Greek-speaking Cyprus became a durable contact zone during the final
Bronze and early Iron Ages. In the ninth to seventh centuries, Phoenician and
Greek traders, craftspeople, mercenaries, settlers, and religious specialists
moved through ports from the Levant to Crete and Euboea and as far west as
Pithekoussai. The Greek alphabet itself records an intimate adaptation of a
Phoenician technology.

Stories can move in writing, but West gives oral movement its full weight.
Cuneiform learning was specialised and difficult. A Greek singer did not need
to sit in a Babylonian archive with a tablet before him. Interpreters worked
between courts and markets. Migrants entered new communities. Craftsmen
carried cult and story with technique. Bilingual singers could learn a plot,
a formula, or a sequence in one language and perform it in another.

That last figure is compelling and uncertain. West can show multilingual
contact and propose the kind of person able to mediate an epic. He cannot name
the singer who brought the Kumarbi material to a Greek tradition or trace a
Siduri scene from one port to the next. His reconstruction distinguishes the
historical corridor from a particular itinerary. The corridor is documented;
the itinerary is usually a probability.

Several periods may have contributed. Some divine material could have entered
the Aegean in the Late Bronze Age; other elements fit the intensified contact
of the orientalising period. A living oral tradition does not preserve an
immigration stamp. Once received, material can be performed for generations,
combined with older inheritance, and transformed before appearing in a poem
whose written form survives.

## Four strands, one Greek tradition

“Greece copied the East” fails because it treats culture as a manuscript and
influence as transcription. The evidence points to a braid with at least four
strands:

1. **Indo-European inheritance** supplied language, poetic structures, and
   mythic relations shared with traditions far beyond the Near East.
2. **Aegean continuity** carried gods, cult places, titles, and institutions
   through the Mycenaean world and its collapse.
3. **Near Eastern and Anatolian transmission** brought stories, divine types,
   images, procedures, and phrases through centuries of contact.
4. **Greek recomposition** selected, rejected, renamed, reordered, and
   naturalised this material inside local religion and oral poetry.

The strands cannot always be separated. A storm god may combine an inherited
Indo-European profile with Syrian combat material and a local cult. A
succession plot can arrive from Anatolia and then become the charter for
Zeus's specifically Greek order. An eastern narrative scene can enter an
oral-formulaic system whose metre and diction have their own history.

Greek agency is therefore visible in the differences. Hesiod is not less
Greek because Kumarbi stands behind Kronos. The *Odyssey* is not Babylonian
because a strand of its wanderings engages *Gilgamesh*. Cultural achievement
often consists precisely in what a tradition does with received matter. The
Greek poets inherited an interconnected world and made works that no eastern
text could substitute for.

## Where Wheel of Heaven begins

Everything above belongs to the direct layer of this article: comparative
philology, literary history, and plausible human transmission, with
confidence graded inside each. What follows changes evidential category. It
is `speculative` and `framework`, endorsed by Wheel of Heaven and by no
mainstream discipline.{{ footnote(id="4") }}

The canonical anchor is concise. In
{% libref(book="the-book-which-tells-the-truth", chapter=5, verse=54) %}TBWTT 5:54{% end %},
Greece appears among regions where the {% wiki(slug="elohim") %}Elohim{% end %}
maintained bases, with the added statement that its mythology contains
testimonies. Claim 0004 develops one possible content for that statement: the
succession of heaven, the divine wars, the assembly, divine-human unions, and
the punished transfer of knowledge are read as transformed memory of the
{% wiki(slug="theomachy") %}Council–Serpentine conflict{% end %}. Claim 0007
places Greece within the wider sphere of activity whose centre of gravity the
canon locates in the Near East.

West changes the conditions under which that reading can be made. A Greek
parallel cannot be treated as an independent second witness when scholarship
has shown that it travelled from an older eastern tradition. Kumarbi explains
the shape of Hesiod's succession story at the level of literary history. The
Gilgamesh tradition explains part of the *Odyssey*'s wanderings. Any Wheel
reading that ignored those routes would mistake reception for corroboration.

The framework therefore asks a narrower question one level below the route:
could stories transmitted through human channels preserve transformed memory
of a referent older than the surviving texts? The answer recorded by the
project is possible, not demonstrated. Transmission can carry memory; it can
also carry fiction, ritual charter, political theology, and endlessly
recomposed entertainment. Nothing in West's book selects between those
referents.

The distinction yields three constraints:

- No one-to-one equation of Zeus, Teshub, Baal, or Marduk with a named Eloha
  follows from the comparisons.
- No event in the *Odyssey* becomes historical because a related scene is
  older in *Gilgamesh*.
- No documented trade route becomes a canonical mechanism. The stories moved
  through people; the framework makes no rival claim about their journey.

On Wheel of Heaven's reading, the strongest candidate for retained memory is
the architecture, not the costume: a governing assembly divided by policy,
conflict between divine factions, a succession of ruling orders, intervention
in human development, and punishment for unauthorised disclosure. Even there,
literary transmission and social projection remain sufficient alternatives.
The framework has not yet produced a textual particular that they cannot
explain.

## The strongest case against

The counter-case has several independent parts.

First, **transmission suffices**. The human corridor explains the shared
plots, scenes, and formulas without a remembered external event. It is the
simpler account and currently predicts every parallel discussed here.

Second, **a cumulative case can magnify selection bias**. A book that surveys
hundreds of pages and several literatures will find striking matches. The
method is only as strong as its controls: chronology, contact, unusual detail,
and willingness to count differences. West applies those controls unevenly,
as any synthesis of this scale must. Later scholarship may preserve the
central cases while pruning the perimeter.

Third, **structure is not memory by default**. Divine councils resemble human
courts because people imagine the sky through institutions they know.
Succession conflicts and prohibited knowledge recur because they organise
universal problems of authority, generation, and boundary. Structural
anthropology can explain convergence without an event behind it.

Fourth, **oral transmission preserves patterns by changing words**. That
makes long-lived memory possible, but it also makes reconstruction uncertain.
A plot can remain stable while its referent disappears, or acquire a new
referent at every performance. Fidelity cannot be assumed across millennia.

Fifth, **category substitution remains live**. Reading gods as advanced
biological creators may translate ancient religion into the prestige language
of a technological age while leaving its explanatory structure unchanged.
Calling an assembly a council chamber and divine craft biotechnology does not
by itself produce new evidence.

These objections do not cancel the Wheel reading; they define its burden. To
advance beyond `speculative`, it must predict a particular that transmission,
inheritance, social projection, and ordinary myth-making do not already
predict. Until then, the direct result belongs to West and the deeper referent
belongs to the framework.

## What remains after the audit

The case for Near Eastern influence survives because it is larger than its
most famous parallels and more careful than its slogan. Hesiod and Kumarbi
provide an articulated dependence case. The combat traditions show a mobile
family whose differences remain legible. Poetic procedure and diction reveal
contact inside the craft. The *Odyssey* and *Gilgamesh* disclose a strong
narrative relationship without collapsing their heroes. Archaeology and
social history supply several corridors, while refusing us the itinerary of
each tale.

The outcome is neither an autonomous miracle called Greece nor a passive
copyist called Greece. It is a receiving, inventing culture at the western end
of an old and crowded world. Its poets worked with Indo-European inheritance,
Aegean memory, eastern material, and their own transforming intelligence.

For Wheel of Heaven, that result is a foundation and a limit. It places Greek
myth inside the same historical field as Anatolian, Levantine, and
Mesopotamian traditions. It does not prove that the field shares an
Elohimian referent. The rain over Helicon is documented. What lies beneath
the weather remains the question.

## Continue reading

- [*The World Behind the Odyssey*](/articles/the-world-behind-the-odyssey/) — the first article: oral composition, Bronze Age memory, and the divine world Homer assumes.
- [*The East Face of Homer*](/articles/the-east-face-of-homer/) — the second article: the eastern corridor, the limits of literary borrowing, and the canon's two Greek engagements.
- The {% wiki(slug="theomachy") %}Theomachy{% end %} entry compares the divine-combat family across traditions.
- The [Theogony](/library/theogony-woh/) and the [Gilgamesh flood tablet](/library/gilgamesh-woh/) are available in the corpus's own translations.
- The [Theomachy Cross-References](/datasets/theomachy-crossrefs/) dataset exposes the comparison layer passage by passage.