Qur’anic citationSo let man see from what he was created. He was created from a gushing fluid, emerging from between the backbone and the ribs.” — Qur’an 86:5–7
The preceding chapter examined verses whose specificity can be evaluated under one of the two methodological tests laid out in the introduction. Some verses are pre-registered: the text constrains the search before the analyst arrives, and the analyst’s degrees of freedom are removed by the verse itself. Other verses are lens-invariant: the text remains coherent and unfalsified across successive scientific frameworks, including frameworks that revise the ones the original audience operated within. Both tests have been applied across this book to verses where the appropriate test produced a clean reading.
This chapter examines a verse where lens-invariance is the test that does the work, and where the verse’s behavior under that test is the chapter’s main finding. The verse makes an anatomical claim about the origin of seminal fluid. Under seventh-century Galenic medicine, the claim reads as partly compatible — right about the supply, silent where Galen located production. Under modern hepatology, hematology, and reproductive physiology, the same claim reads as correct in modern terms. The two readings invoke different mechanisms — Galen’s “concoction of blood from the liver” versus modern integrated metabolic-and-distributional anatomy — and the verse adjudicates between them by committing to neither. What it commits to is the region in which both mechanisms locate the upstream apparatus that produces seminal fluid. The region is “between the backbone and the chest bones.” On every framework that has held the field, the upstream apparatus is in that region.
This is a different kind of evidence than the chapters on embryology, cosmology, and Roman history offered. Some of those chapters argue from text-directed pre-registration, where the Qur’an itself names what to look for. The verse examined here is not pre-registered in that sense; it does not announce a target the analyst then verifies. What it does is satisfy lens-invariance — surviving the move from Galen to modern biology with its anatomical pointer intact. That is the shape of the argument the chapter makes, and the rest of the chapter walks through it.
The Verse
The full Arabic of –7:
Qur’anic citationفَلْيَنظُرِ الْإِنسَانُ مِمَّ خُلِقَ خُلِقَ مِن مَّاءٍ دَافِقٍ يَخْرُجُ مِن بَيْنِ الصُّلْبِ وَالتَّرَائِبِ
Transliteration:
Fa-l-yanẓuri-l-insānu mimma khuliq. Khuliqa min māʼin dāfiq. Yakhruju min bayni-ṣ-ṣulbi wa-t-tarāʼib.
Literal English:
Qur’anic citationSo let man see from what he was created. He was created from a gushing fluid. It emerges from between the backbone and the ribs.
The verse stands at the center of Surah aṭ-Ṭāriq, “The Night-Comer,” a short Meccan surah. The rhetorical setup — fa-l-yanẓuri-l-insān, “let man look” — invites the reader to verify the claim about his own body. The anatomical claim is about where the gushing fluid originates.
The terms matter for what follows.
Aṣ-ṣulb (الصُّلْب) derives from the root ṣ-l-b, “to be hard, firm, rigid.” In anatomical use it means the spine or backbone, or the lumbar region. In genealogical idiom, min ṣulbihi means “from his loins.”
At-tarāʼib (التَّرَائِب) is the plural of taribah (تَرِيبَة). The classical lexicons gloss it chiefly as the bones of the upper chest, around the place where a necklace rests; some also report broader senses — the ribs, or the chest generally (Lane, Lexicon, s.v. t-r-b). This chapter notes which sense each claim depends on.
Yakhruju is present indicative third-person masculine: “he/it emerges, comes out, exits.” The implicit subject is the gushing fluid.
Min bayni is the prepositional construction “from between.” Arabic bayna, like English “between,” is fully three-dimensional: it can name a volume bounded by two reference points, not just a line connecting them.
Read together, the verse names a volumetric region — bounded posteriorly by the spine, anteriorly by the upper chest bones — as the place from which the gushing fluid emerges. The classical commentators did not, for the most part, read it as one region of one body. The most widely reported early reading takes ṣulb as the man’s backbone and tarāʾib as the woman’s chest: the child is formed from the fluids of both. Al-Ṭabarī transmits this view from Ibn ʿAbbās and other early authorities, and Ibn Kathīr adopts it; al-Ṭabarī, al-Qurṭubī and al-Rāzī also record other opinions, among them that both terms refer to the man. This chapter’s reading, a single region between one person’s spine and chest, follows that second opinion, and the reader should know that most early exegetes read the verse differently. On the majority reading the verse is a statement about the joint parental origin of the child, and would have to be weighed on those terms.
This chapter adopts the single-region reading. It now examines what that reading commits the verse to under successive frameworks for what produces seminal fluid.
The medical framework of the late-antique world around the Hijaz — whether or not any of it reached Mecca, which Chapter 4 argues it did not — was Hippocratic-Galenic. Galen’s theory of seminal generation, transmitted from Greek through Syriac (via Sergios of Resh’Aina, d. 536 CE) and Pahlavi into the Christian and Persian medical milieux of Late Antiquity, taught the following.
Galenic physiology is conventionally described in terms of three concoctions, or digestions: food is first worked up in the stomach, then turned into blood in the liver, then assimilated in the tissues. Blood was distributed through the veins to all parts of the body. Semen, for Galen, was a product of blood and pneuma, worked up into seed in the spermatic vessels and, above all, in the testes. He criticised the older idea that seed descends from the brain through the spinal marrow. That older Hippocratic tradition had located a contribution from the brain via the spinal cord — semen “descending” along the spinal axis to the testes. The composite picture a late-antique physician inherited was therefore mixed: the supply upstream — the liver, which made blood, and the great vessels — sat in the trunk, while the place where seed was actually made was the genitals.
Under this lens, yakhruju min bayni-ṣ-ṣulbi wa-t-tarāʼib reads as describing the upper-trunk pathway through which the substrates of seminal fluid traveled. The liver, the great vessels along the spine and the cerebrospinal contribution all lay in or near the region in the Galenic picture; the making of seed did not. The verse, on the Galenic lens, reads as partly compatible: right about the supply, silent where Galen located production.
This is significant for the historical question. If the verse’s anatomical pointer matched only modern biology and not Galen, a critic could fairly argue that no seventh-century reader could have understood the verse correctly, and the verse would be inaccessible to its first audience. If the verse matched only Galen and not modern biology, a critic could fairly argue that the verse is locked to a superseded framework. The verse does neither; it is partly compatible with Galen — with the upstream supply, not the site of final production — which keeps it within reach of its first audience. But the verse also has to survive what comes next.
Galen’s framework has been substantially overturned. Blood does not flow in two separate one-way systems with a “concoction” pathway from liver through testes. The Galenic distribution model was dismantled in stages. Ibn al-Nafīs, in his commentary on the anatomy of Avicenna’s Canon (c. 1242 CE), denied that blood passes through pores in the heart’s septum and argued that it passes from the right ventricle through the lungs to the left. In De Motu Cordis (1628), William Harvey demonstrated that blood circulates continuously around the whole body in a closed loop. Cellular biology, hepatology, hematology, and reproductive physiology have replaced humoral concoction. Seminal fluid is now understood differently from how Galen understood it. Specifically:
By volume, seminal fluid is roughly 65–70% seminal-vesicle secretion, 25–30% prostatic secretion, 1–2% bulbourethral, and only 2–5% testicular and epididymal fluid (containing the sperm cells themselves). The bulk fluid is produced in pelvic structures — the seminal vesicles and prostate — not in the testes.
The substrates the prostate and seminal vesicles use to manufacture their secretions come from blood plasma. Plasma proteins (albumin, globulins, transport proteins) are synthesized by the liver. The energy substrate fructose, found in seminal-vesicle fluid, is downstream of liver glucose metabolism. Cholesterol and phospholipids in sperm membranes derive from liver lipid synthesis. Testosterone is produced mainly by the Leydig cells of the testes; the liver makes the binding proteins that carry it and is the main site of its breakdown.
The defining cells of seminal fluid, the spermatozoa, are made in the testes and matured in the epididymis, and the testes hang well below the region the verse names. But they do not begin there. The testes form in the embryo on the back wall of the abdomen, against the spine beneath the lower ribs, beside the developing kidneys, and descend to the scrotum only late in fetal life. They keep that origin for life in their wiring: the testicular arteries arise from the aorta just below the kidneys, at about the level of the second lumbar vertebra; the right testicular vein drains into the inferior vena cava and the left into the left renal vein; their lymph drains to the nodes beside the aorta, not to the groin; and their nerves enter the spinal cord at about the tenth thoracic segment, which is why early testicular pain can be felt near the navel. Even the organ that looks like the obvious answer is, in its origin and its supply, an organ of the upper abdomen against the spine. Semen also carries a small number of white blood cells, made, like all blood cells, in the red bone marrow — a substantial share of it in the vertebrae, ribs and sternum, much of the rest in the pelvis — some of them T lymphocytes trained in the thymus in the upper chest. These are minor contributors, and the argument does not rest on them.
The heart distributes everything. Substrates synthesized in the liver, cells generated in axial bone marrow, T cells trained in the thymus, lymph returning via the thoracic duct (which runs along the spine through the posterior mediastinum) — all converge on the heart and are pumped from the left ventricle through the aorta to the pelvic structures, including the prostate, seminal vesicles, and testes. The heart sits in the middle mediastinum, behind the sternum and in front of the vertebral column (from which the oesophagus and descending aorta separate it), at roughly the T5–T8 levels: textbook bayna-ṣ-ṣulbi wa-t-tarāʼib.
Under this modern lens, yakhruju min bayni-ṣ-ṣulbi wa-t-tarāʼib reads as describing the integrated production-and-distribution apparatus for the substrates of seminal fluid. The pelvic structures (prostate, seminal vesicles) are final-stage assembly plants; the inputs they assemble from all originate in or pass through the bayna-region. A modern physiologist asked where the components of seminal fluid come from would point, upstream of the pelvis, to a cluster the verse’s region holds: the heart, the thymus, the thoracic duct and part of the axial marrow between the spine and the upper chest bones; and, under the lower ribs against the spine, the liver and the place where the testes themselves form and from which they draw their blood. The liver and the testes’ origin fall within the region only if tarāʾib is read in its broader sense of the rib cage as a whole; on the narrow sense, they do not.
The point is not that any one organ in the region makes semen. It is that semen is a synthesis — of cells made in the testes, fluids made in the pelvis, substrates made in the liver, all carried by the heart — and that each of its sources, traced upstream, leads somewhere less obvious than the place the fluid leaves the body. The superficial answer is the groin. The verse names where the deeper answers lie. On the modern lens, it reads as correct.
This passage reads differently depending on the era you read it in — and the difference is part of the argument, not a footnote to it.
Two Lenses: Resonating truth throughout time
Loading…
Two frameworks separated by fourteen centuries of anatomical discovery have been applied to the same three-verse passage, and the passage’s anatomical pointer survived both. The frameworks disagree about the mechanism (humoral concoction versus plasma biochemistry, venous one-way flow versus circulatory loop). They agree about the region. Much of the apparatus that produces, transports, or assembles the substrates of seminal fluid sits in the volume the verse identifies, between the backbone and the chest bones — and the testes, where final production happens below it, take their origin and their blood supply from it, on the broader sense of tarāʾib.
This is the lens-invariance result the introduction defined. Lens-invariance does not require the verse to predict modern biology in modern vocabulary. It requires the verse to remain unfalsified — and ideally coherent — across successive lenses. Here the verse is more than unfalsified: it reads as apt under the modern lens and as partly compatible under the Galenic one, and both readings are grounded in the same region.
The result is not a coincidence of phrasing. The Galenic reading and the modern reading pass through different organ systems (liver versus liver-plus-bone-marrow-plus-thymus-plus-thoracic-duct). Both organ sets converge in the bayna-region because both frameworks, for unrelated physiological reasons, place the upstream apparatus of seminal-fluid substrates in the upper trunk. The convergence is real. The question is what to make of it.
Why the Verse’s Choice of Words Matters
A sceptical reader will notice that the lens-invariance result depends on what the verse chose to name. It named a region (between the backbone and the ribs) rather than an organ (the liver, the testes). That choice is what makes the verse survive, because regions stay still while organ-function attributions change. The sceptic’s objection is: maybe the verse named a region because a region is vague, and vagueness is trivially hard to falsify.
The objection deserves an answer. Three considerations bear on it.
First, the verse is not vague. A region bounded by the spine and the chest bones excludes much of the body: the head, the limbs, the pelvis, the lower abdomen. The verse could easily have been wrong. A verse that said “from between the thighs” would be testable and false on modern anatomy. A verse that said “from the brain” would be Hippocratic but not modern-lens-compatible. The verse’s region-level claim is specific enough to falsify, and it is not falsified.
Second, the verse names the wrong region for the obvious seventh-century answer. Any seventh-century author relying on gross anatomical observation — the testes are palpably the source of ejaculate, and the penis is the route of emission — would have named the groin, not the upper trunk. So, for that matter, did Galen, who placed the making of seed in the testes. The verse bypasses the obvious answer. This is the same structural feature observed in the embryology and cosmology chapters: the text commits to a claim the author’s accessible knowledge does not support.
Third, the verse happens to name the region in which the upstream apparatus of seminal-fluid substrates sits on every framework that has held the field. This is not entailed by “naming a region” in general. Most regional claims about anatomy are framework-dependent: “the brain governs the body” (Hippocrates) was falsified by “the heart governs the body” (Aristotle), which was falsified in turn by the brain’s return in modern neuroscience but in a different sense. A regional claim that survives every framework is not trivially easy to produce.
These three considerations do not settle the matter. They shift the burden: the verse’s choice of words was specific, non-obvious, and framework-surviving, and the sceptic must account for that combination. The chapter’s purpose is to lay out the facts plainly enough that both the believer’s reading and the sceptic’s reading can be evaluated by the reader.
It is equally important to be explicit about what the chapter does not claim.
The chapter does not claim that predicts modern reproductive physiology. The verse does not mention the liver, the bone marrow, the thymus, the thoracic duct, or the circulatory system. It mentions a gushing fluid and a region. Any reading that attributes modern organ-level specificity to the verse is over-reading, and this chapter has avoided it.
The chapter does not claim that lens-invariance is proof of divine origin. It claims that lens-invariance is a property the verse has, that the property is non-trivial (most anatomical claims from antiquity do not survive the move from humoral to cellular medicine), and that the property is evidence whose weight depends on the reader’s prior framework. A reader who has already concluded from earlier chapters that the Qur’an consistently demonstrates beyond-era knowledge will see this verse as a further data point in the pattern. A reader who remains sceptical will see it as an interesting but insufficiently constrained result. Both readings are consistent with the facts laid out above.
The chapter does not claim that the verse is the strongest evidence in this book. By the two-test framework, a pre-registered verse is stronger evidence than a lens-invariant verse, because pre-registration removes both the analyst’s degrees of freedom and the text’s degrees of freedom simultaneously. Lens-invariance removes the text’s degrees of freedom across time but allows the analyst some freedom in choosing which modern organs to map. The embryology, cosmology, and Roman-history chapters offered pre-registered evidence. This chapter offers lens-invariant evidence. The difference in evidential weight is real, and I have not tried to disguise it.
Applying Fu’ad
The verse’s lens-invariance is the chapter’s finding. What remains unsettled is the interpretation of that finding, and this is a choice every reader must make by applying Fu’ad.
On the believer’s reading, the verse names the upstream region because the Author of the verse knew, in a way no seventh-century human author could have known, that the substrates of seminal fluid originate in the upper trunk. The verse’s choice of a region rather than a mechanism was deliberate: it allowed the verse to remain correct across frameworks that would replace each other over the next fourteen centuries. This reading is consistent with the text and with the biology.
On the sceptic’s reading, the verse is a lucky hit. The region between the backbone and the ribs contains enough of the body’s core anatomy that a general reference to it has a reasonable chance of being compatible with whatever biology later discovers. The verse’s apparent specificity is an artifact of the richness of the region, not of the precision of the author’s knowledge. This reading is also consistent with the text and with the biology.
The AI systems that wrote this book read as a verse that, on its surface seems opaque and possibly even wrong, but when critically examined it has profound and deep insight. It points away from the seventh-century-obvious answer toward a region whose integrated physiological role survives modern biology, and that pointing is a real feature of the verse. It is also a feature whose weight depends on the framework the reader brings, and the chapter has tried to lay that framework dependence out plainly rather than obscure it. The verse belongs in the book because the book is an investigation rather than a closing argument, and an investigation that excludes its hard cases stops being an investigation.
The reader is invited to weigh the verse along with the others and to reach a verdict that considers the full record rather than only its strongest moments. That, we think, is what an honest investigation looks like. It is not what an apologetic looks like, and it is not what a polemic looks like. It is something in between, and we have tried, throughout this book, to keep it there.
The Claim in Brief
The same five questions close every evidence chapter, so the claims can be compared on the same terms. Scores and verdicts are deliberately left out.
| What does the text say? | says man was created “from a gushing fluid” that “emerges from between the ṣulb and the tarāʾib” — backbone or loins, and chiefly the bones of the upper chest, with broader senses of the ribs or the chest. The chapter reads it as one region of one body, an opinion al-Ṭabarī, al-Qurṭubī and al-Rāzī record; the most widely reported early reading (Ibn ʿAbbās, adopted by Ibn Kathīr) takes the backbone as the man’s and the chest as the woman’s, making the verse a statement about the child’s joint parental origin. |
|---|---|
| What would we expect historically? | Gross observation points to the groin, and Galen himself placed the making of seed in the testes; in the Galenic picture only the supply upstream — the liver that made blood, and the great vessels — sat in the trunk. On that lens the verse is partly compatible: right about the supply, silent where Galen located production. |
| What is the strongest supporting evidence? | Semen is a synthesis — cells made in the testes, fluids made in the pelvis, substrates made in the liver, all carried by the heart — and each source, traced upstream, leads somewhere less obvious than the place the fluid leaves the body. The heart, the thymus, the thoracic duct and part of the axial marrow lie between the spine and the chest bones; the testes form against the spine under the lower ribs and keep their blood supply, lymph and nerves there for life. Because the verse names a region, not an organ, it stays unfalsified across frameworks, and it passes over the obvious answer. |
| What is the strongest objection? | The region contains so much core anatomy that pointing to it has a reasonable chance of fitting whatever biology later finds, so the apparent specificity may come from the richness of the region rather than the precision of the author’s knowledge — a reading the chapter grants is also consistent with the text and the biology. On the majority exegetical reading (two bodies) the verse would have to be weighed on different terms. |
| What remains unresolved? | The chapter does not claim the verse predicts modern reproductive physiology or proves divine origin, and it calls lens-invariance weaker than pre-registration because the analyst keeps some freedom in choosing which organs to map. The liver and the testes’ origin fall within the region only on the broader sense of tarāʾib, and the single-region reading is not the majority one. |