To call something unknowable is already to claim knowledge of it. For centuries, mystics and theologians have said that God exceeds every concept; in saying so, they drew a border and planted a flag on it. Where does such knowledge come from? What gives reason the right to map a frontier it has never crossed?
The question runs through three traditions that never met, two rooted in Mexican soil. In medieval Provence and Spain, Kabbalists named God Ein Sof, “without end,” and then spent generations describing what flows from a source they had declared beyond description. Nahua poets of central Mexico asked whether life on earth is truly lived; their word for truth, neltiliztli, has inspired some of the boldest readings in the study of Mexican philosophy. Sor Juana Inés de la Cruz, the seventeenth-century Mexican nun, moved the frontier inside the mind: her poem Primero Sueño sends the intellect to grasp the whole of creation at a single glance and records its collapse in one devastating line, “y por mirarlo todo, nada vía” (Sor Juana Inés de la Cruz 1951, v. 480). Trying to see everything, it saw nothing.
Defeat alone teaches nothing. The intellect must still learn whether the world, its own powers, or its chosen method is to blame. Once it identifies which and explains why, its ignorance ceases to be blind. Knowledge of a limit begins where reason identifies the point at which a particular claim loses its footing, even when what lies beyond that point remains unknown.
Contents
The Paradox of Knowing a Limit
Ein Sof: Can the Infinite Be Defined?
Neltiliztli: What Did Truth Mean in Aztec Thought?
Life on Earth: Mortality and the Limit of the Knower
Flower and Song: What Can a Symbol Know?
Sor Juana’s First Dream: How Failure Becomes Knowledge
Conclusion: Knowing Where Knowledge Ends
The Paradox of Knowing a Limit
The paradox predates Sor Juana’s poem. Kant separated a boundary, which presupposes a space beyond itself, from a mere restriction, which only negates (Kant 2004, §57). Hegel’s reply was that a limit recognized as a limit has, in that very act, already been passed (Hegel 2010, 106). In the preface to the Tractatus, Wittgenstein observed that to draw a limit to thought we would have to think both sides of it (Wittgenstein 1922, 27). Graham Priest has traced this family of paradoxes across the history of philosophy and argued, controversially, that their structure is genuinely contradictory (Priest 2002, 2–8, 71–109). The immediate question is narrower: when an intellectual procedure fails, what does the failure entitle us to conclude?
In the fifteenth century Nicholas of Cusa turned ignorance into a discipline. His docta ignorantia, learned ignorance, describes a finite mind that understands that no proportion holds between the finite and the infinite; that recognition already counts as knowledge (Nicholas of Cusa 1981, I.1–3). In our own time Nicholas Rescher has shown how every claim of unknowability depends on the kind of access and inquiry in play (Rescher 2009, 1–10, 21–38).
Claims about limits occupy three epistemic statuses. An asserted limit is announced before its necessity has been established. A justified limit arises once a definite task has been specified and the failure of a given cognitive operation has been explained. A limit becomes reflexively known when that failure discloses something about the relation between the operation and its object. Reflexive knowledge presupposes a sound diagnosis. Frustration, however keenly felt, is not yet knowledge.
The word “unknowable” hides a further ambiguity. An essence may be closed to us while its manifestations stay open. Where literal description fails, a symbol may still speak, and the collapse of one method says nothing yet about another. Kabbalah, Nahua poetry, and Sor Juana’s poem stage these distinctions under different historical conditions. No line of transmission connects Nahua thought with medieval Kabbalah, and the Infinite of the Kabbalists is not teotl. That divergence is essential: any comparison that equated their objects would overstep its evidence before it began.
Ein Sof: Can the Infinite Be Defined?
Ein Sof means “without end.” The phrase became a technical term among the Kabbalists of Provence and Gerona in the early thirteenth century, in the circle of Isaac the Blind and his disciple Azriel, and it carries a provocation inside its grammar. To define is to mark an object off from everything else, to draw its edge. A name made of a denied edge refuses that operation at the root. Yet, as Gershom Scholem and Moshe Idel have shown, the Kabbalists never agreed on how Ein Sof relates to the sefirot, the ten articulated aspects through which the hidden God becomes manifest. That disagreement matters epistemically: no single formula can tell us what every school believed had been disclosed (Scholem 1987, 265–80; Idel 1988, 136–53).
The danger they faced had already been named in Jewish philosophy. In the Guide of the Perplexed, Maimonides warns that every affirmative attribute drags God toward the likeness of created things; only negation keeps language from claiming more than it grasps (Maimonides 1963, I.58). The Kabbalists built a theology far from his austere rationalism, a living order of divine disclosure. What they shared with him was a fear of the misplaced predicate. Denying an attribute of God never amounts to knowing the essence of which it is denied; the distinction between negation and knowledge of essence remains crucial in both contexts.
The Sefirot: What Disclosure Allows Us to Say
The sefirot make theological speech possible. Read as emanations, powers, or aspects of divine life, they carry different ontological commitments, yet each reading leaves the interpreter an ordered set of relations open to analysis, even where the source behind them eludes definition (Idel 1988, 136–53). The epistemic issue is what that speech entitles us to infer.
The Zohar sharpens the problem. Its account of emanation opens with a spark of darkness flashing within the most concealed, “from the head of Infinity” (Zohar 1:15a; Matt 2004, 107–9). The text names the source only as the place from which disclosure breaks out; it never describes it. That restraint matters for interpretation. An account that separates source from manifestation can sustain analysis of the relations it lays out, but a property assigned to the manifest order does not thereby belong to its source. Zoharic literature also contains distinct strata, and a sentence torn from its layer can borrow the false authority of an undivided “Zohar” (Scholem 1995, 159–62).
The boundary falls at a precise point: the leap from the disclosed order to a full account of its ground. The relations presented by the sefirotic order remain open to analysis; the claim that they reveal the divine essence entire needs support of its own. A declaration that Ein Sof is absolutely unknowable overreaches in the opposite direction, since a single failure of predication proves nothing so total. The defensible conclusion is narrower: an object-related limit appears where an object conceived as infinite confronts a mode of thought that determines by drawing edges. That mismatch blocks one specific transfer of predicates. Theology and philosophy are left with a great deal still to do.
Neltiliztli: What Did Truth Mean in Aztec Thought?
The Nahua, the Nahuatl-speaking peoples of central Mexico among whom the Mexica, or Aztecs, rose to power, approached the problem from another side. Here the pressure comes from the instability of everything on earth. How can anyone speak truly about a world that will not hold still?
A Word and Its Interpretations
The lexical record is plain. In his Vocabulario of 1571, the Franciscan Alonso de Molina glosses neltiliztli simply as “verdad,” truth (Molina 1571, pt. 2, fol. 66v, col. 2). Modern philosophy has asked far more of the word. Miguel León-Portilla and James Maffie connect words built from the root nel- with genuineness and rootedness, and each develops an account of truth as a way of standing in relation to reality, more than a property of correct sentences (León-Portilla 1963, 8; Maffie 2002, 75, 80). Their philosophical fertility does not settle their historical validity; actual usage remains decisive, and Molina’s single entry cannot carry the argument alone.
Poetry offers firmer ground. One of the songs in the Cantares Mexicanos asks, “huelle nelli nemoa in tlalticpac”: is life on earth truly lived? (Cantares Mexicanos 2012, song VI, fol. 3v, §33). The word nelli, “truly,” stands at the center of a mortal question, placing truth inside a question about lived existence. The line supports no universal definition of neltiliztli as existential authenticity. Within this poem, a purely abstract notion of truth fits poorly.
Translation is where the next danger lies. The translator who turns a question about living “truly” into a systematic thesis about “rootedness” has crossed from transcription into interpretation. Such a move requires argument. When the interpretive addition is quietly credited to the original text, it becomes an unearned claim to knowledge, and a corpus that crossed languages and passed through colonial institutions is especially vulnerable to that distortion.
Teotl and a World in Motion
The songs repeatedly return to the impermanence of what people hope will last. Maffie builds this instability into a full metaphysics: teotl, in his reading, is a single self-transforming process, and individual things are its passing configurations (Maffie 2014, 21–23, 38). The reconstruction is contested (Kostićová 2025, 178–206), and the poems alone do not establish it. As a philosophical reconstruction, however, it poses a useful test: if reality is process, what does a description lose when it treats a changing configuration as a fixed thing?
An answer requires concrete examples of distortion. The appeal of a process ontology is insufficient. A classification can correctly identify a recurring pattern and still hide the movement that sustains it, much as a map of a river records its banks and says nothing of the current. Here the limit is methodological: a form of representation excludes features the inquiry has reason to count as essential. Neltiliztli draws attention to the standards by which truth is recognized; Maffie’s teotl offers one influential and disputed hypothesis about the reality those standards must answer to.
The Historian’s Own Limit
Molina also records Tloque Nahuaque (Molina 1571, pt. 2, fol. 148r, col. 1), often rendered “Lord of the Near and the Nigh” (Sahagún 1961, 32), but he records it inside a Christian colonial vocabulary. The entry proves a sixteenth-century usage. Whether that usage preserves an older indigenous metaphysics is another question, and its answer depends on sources the dictionary cannot supply. A name kept in a missionary’s lexicon cannot carry the whole weight of a preconquest doctrine of the Absolute.
The case turns the epistemology of the limit into a rule of source criticism. The record supports an attestation and its context; a claim about an entire earlier theology crosses a boundary that can be located precisely. Refusing that claim is more than scholarly caution. The reasons for withholding it can be stated, and once stated they become knowledge in their own right: knowledge of how far the archive reaches.
Life on Earth: Mortality and the Limit of the Knower
In Tlalticpac, “On Earth”
In tlalticpac, “on earth,” is the stage on which Nahua poetry seeks truth and loses life. In the songs associated with Nezahualcoyotl, even the things that seem made to last become emblems of passing: jade shatters, gold breaks, the quetzal plume is torn (Cantares Mexicanos 2012, fol. 17r, §§266–67). The image unsettles because it strips endurance from the very objects through which people imagined it. What survives? The question sharpens; the evidence still leaves the answer open.
Such songs make finitude a condition of inquiry. No one who asks them stands at a timeless vantage point from which the whole course of existence could be surveyed. Mortality intensifies the demand for an enduring ground and leaves its existence and nature to be argued for. Urgency, however great, proves nothing about the answer.
Nezahualcoyotl and the Problem of Attribution
Nezahualcoyotl, the fifteenth-century ruler of Texcoco, has become the emblem of Nahua reflection on death. The songs transmitted under his name are indispensable evidence of a poetic and intellectual tradition, yet they were written down in the colonial period, and, as John Bierhorst’s editions make clear, the claim that a given song is his own often cannot be secured (Bierhorst 1985, 101–6). The evidence supports study of questions recurring across the corpus without requiring a reconstructed system belonging to one author. Claims about Nezahualcoyotl’s personal doctrine carry a heavier burden of proof, one the surviving sources rarely meet.
The Knower’s Own Limit
Awareness of death establishes one fact with certainty: the knower’s time and chances for verification are finite. It supplies no comparable evidence about an afterlife or the ultimate ground of existence. The limit now lies in the knower. A subject-related limit arises from the situation of the inquirer: a perspective, a place in time, finite resources of attention and proof. To recognize these conditions is already to judge more precisely, even when the question that prompted the judgment stays unanswered.
Finitude founds no metaphysics of survival, yet it changes the terms of inquiry. A mortal investigator cannot wait for a verification that would take forever. The question of permanence has to be asked under conditions the question itself cannot remove, and this sets the subject-related limit apart from the failure Sor Juana stages in her poem. Death bounds the time of the knower. Sor Juana’s intellect meets a different barrier, inside the very operation by which it seeks to understand.
Flower and Song: What Can a Symbol Know?
In Xochitl, in Cuicatl
The difrasismo in xochitl, in cuicatl, “flower and song,” became central to Miguel León-Portilla’s account of Nahua poetry and philosophy (León-Portilla 1963, 74–79, 140). One song in the Cantares Mexicanos says: “ye nel ticyacahua in xochitla ya yhuan in cuicatl,” we truly leave the flowers and the songs behind (Cantares Mexicanos 2012, song LXX, fol. 61r, §1256). The word of truth returns, nel, at the moment of departure. Beauty and loss arrive in one breath. A song lives only while it sounds and while someone remembers it; a flower’s splendor lasts as long as its opening. Neither image promises a way out of death.
The interpretation must preserve that restraint. A second song links death with the loss of human works and songs (Cantares Mexicanos 2012, song LIV, fol. 36r, §682). Together these passages show poetry as a way of dwelling on transience, of holding it in view without flinching. Any stronger claim—that poetry itself opens a path to ultimate truth—requires further argument, despite León-Portilla’s suggestion. The distance between what the poems say and what philosophy builds on them marks a boundary of its own, the boundary of interpretation.
Radiance and Concealment
Kabbalistic writing likewise thinks through images: light poured out and light withheld, as Scholem and Idel have traced across its history (Scholem 1995, 27–28; Idel 1988, 218). Radiance can express dependence on a source while leaving the nature of that source unspoken; the Zohar’s spark of darkness, flashing from Ein Sof, does exactly this (Zohar 1:15a; Matt 2004, 107–9). Nahua flower and song belong to another world of performance, memory, and mortality. Their comparison is strongest at the level of function: both hold together relations that a literal description would break apart.
That power also carries a danger. Because a symbol holds several relations at once, a reader can slip into it an attractive metaphysics its historical use never supported. Language forms the final locus of limitation. A linguistic limit appears when literal speech distorts what the interpreter is trying to convey. Symbolic expression offers another resource, but it answers to the same demand for evidence. The richness of an image is no substitute for establishing what it meant in its own text.
The Limit of Comparison
Comparison itself is subject to the same rule. A structural likeness between two symbolic practices licenses an inquiry into how images carry relations. It offers no warrant for identifying their sacred referents or for assuming that Kabbalists and Nahua poets faced the same religious problem. An epistemology of the limit binds the comparative philosopher as strictly as it binds the texts under comparison.
Sor Juana’s First Dream: How Failure Becomes Knowledge
The Ambition to See Everything
Primero Sueño, published in 1692, is a poem of 975 lines about a single night (Paz 1988, 357; Sor Juana Inés de la Cruz 1951, vv. 1–975). The body sleeps, and the soul rises to take in the whole of creation at once. Sor Juana turns the problem of epistemic limits into an event the reader watches unfold. The intellect is first impeded by the sheer excess of its objects (Sor Juana Inés de la Cruz 1951, vv. 450–53), and then comes the collapse: “y por mirarlo todo, nada vía” (Sor Juana Inés de la Cruz 1951, v. 480). The defeat makes sense. An ambition to see everything at once destroys the discrimination on which all seeing depends. Nothing is announced in advance; the reader witnesses a procedure giving way.
Octavio Paz set this ambition within Sor Juana’s intellectual and literary world (Paz 1988, 357–86). The poem’s methodological structure has been studied by Adolfo Sánchez Vázquez, and Verónica Volkow Fernández reads its ascent against the anagogical tradition (Sánchez Vázquez 2002, 49–63; Volkow Fernández 2017, 131–56). Their work already establishes that the poem stages failures of intuitive and discursive knowledge. The question pursued here is narrower: what epistemic standing belongs to the lesson drawn from those failures?
The Revision of Method
The intellect does not stop at its first defeat. It resolves to proceed by degrees, rung by rung, from the lowest grade of inanimate being upward: “De esta serie seguir mi entendimiento / el método quería” (Sor Juana Inés de la Cruz 1951, vv. 617–18). The word método carries the weight of the passage. By changing procedure, the poem separates the failure of simultaneous vision from the larger question of whether ordered inquiry can succeed. That failure becomes epistemically informative once the ambition and mode of operation of the first approach are brought into view.
Step-by-step inquiry preserves distinctions the totalizing glance destroyed, and it exposes the price of finite attention: every step depends on what has been chosen, set aside, and carried forward. Sor Juana’s intellectual drama grows from this double movement. Inquiry takes on a more disciplined shape and, in the same motion, learns that no method coincides with the totality it seeks.
From Failure to Reflexive Knowledge
Together, the failed ascent and the revised method form a model of reflexive knowledge. The collapse of the first attempt becomes intelligible only in the light of the second, which makes the earlier procedure available for diagnosis. What the poem establishes is a limit on one particular ambition to grasp the whole. It offers no proof that reality is unknowable in every respect, and it would lose its philosophical force if made to carry one.
Reflexivity begins when the knower accounts for a failure beyond the bare fact that it happened. The conditions of the task become clear, and with them the grounds for withholding a stronger claim. The poem closes on dawn and a single waking self: “el mundo iluminado, y yo despierta,” the world lit up, and I awake (Sor Juana Inés de la Cruz 1951, v. 975). The universe remains unconquered. What the intellect carries into the morning is its own measure, and that is knowledge.
When Is a Limit Known?
Where a Limit Arises and What Standing It Has
Two questions organize every case. The first asks where a restriction arises: the object as described, the method employed, the situated subject, or the resources of language. The second asks what epistemic standing the claim has: asserted, justified, or reflexively known. The two classifications are independent. An object-related limit may still be only asserted, and a methodological one may be justified without ever becoming reflexive.
Justification has three conditions: a specified task, an account of why the attempt failed, and a conclusion that goes no further than that account supports. Reflexive knowledge adds an articulated insight into the cognitive relation. Compare two sentences. “This method failed” records an event. “This method failed because its demand for simultaneous comprehension exceeded the capacity for discrimination the task required” identifies the source of failure and provides grounds, without presuming to legislate the limits of every conceivable intelligence.
What the Three Traditions Show
The cases resist reduction to a single metaphysical scheme, and that resistance is part of the result. Each tests the same demand for justified inference under different conditions. The historian’s discipline turns out to be continuous with the philosopher’s: the scholar weighing a colonial dictionary entry and the mystic speaking of an infinite source answer to one rule.
| Case | Where the limit arises | What fails | What becomes known |
| Ein Sof | Object | Definition by drawing edges, applied to the infinite | Which predicates may not pass from manifestation to source |
| Neltiliztli and teotl | Method | Fixed categories applied to a world in motion | What a description loses when it freezes a process |
| Tloque Nahuaque in Molina | Method (source criticism) | Inference from one colonial entry to a preconquest doctrine | How far the archive reaches |
| In tlalticpac | Subject | The hope of a timeless vantage point | The finite time and perspective of the knower |
| In xochitl, in cuicatl | Language | Literal description of transience | What symbols can hold, and where interpretation outruns them |
| Primero Sueño | Method | Simultaneous vision of the whole | The intellect’s own measure; the limit becomes reflexively known |
Conclusion: Knowing Where Knowledge Ends
A limit becomes an object of knowledge when the failure of a specified claim has been explained and the conclusion drawn from it stays within the evidence. Such knowledge concerns a relation: between a knower, the task undertaken, the means of inquiry, and whatever those means encounter. It remains substantial even when the nature of what exceeds the claim remains unknown.
The same question disciplines every reading in this comparison: which inference has reached the end of its grounds, and why? To answer it is an achievement of reason. What lies further on is left open to inquiry, and the unknown is never mistaken for a possession of thought.
The mystics who declared God beyond every concept planted a flag on a border they had never crossed. Read honestly, that flag records how far reason walked, and nothing beyond it. Reason has every right to plant it there, on its own side of the line, provided it says where the line runs and why.
Sources and Further Reading
Translations from Nahuatl, Spanish, and Aramaic are the author’s unless otherwise noted.
Primary Sources
Bierhorst, John, trans. and ed. 1985. Cantares Mexicanos: Songs of the Aztecs. Stanford, CA: Stanford University Press.
Cantares Mexicanos. 2012. Paleography and translation by Miguel León-Portilla, Librado Silva Galeana, Francisco Morales Baranda, and Salvador Reyes Equiguas; digital edition by Salvador Reyes Equiguas. Temoa, Universidad Nacional Autónoma de México. Accessed October 8, 2026.
Hegel, G. W. F. 2010. The Science of Logic. Edited and translated by George di Giovanni. Cambridge: Cambridge University Press.
Kant, Immanuel. 2004. Prolegomena to Any Future Metaphysics. Translated and edited by Gary Hatfield. Rev. ed. Cambridge: Cambridge University Press.
Maimonides, Moses. 1963. The Guide of the Perplexed. Translated by Shlomo Pines. 2 vols. Chicago: University of Chicago Press.
Matt, Daniel C., trans. and comm. 2004. The Zohar: Pritzker Edition. Vol. 1. Stanford, CA: Stanford University Press.
Molina, Alonso de. 1571. Vocabulario en lengua castellana y mexicana y mexicana y castellana. Mexico City: Antonio de Spinosa.
Nicholas of Cusa. 1981. Nicholas of Cusa on Learned Ignorance: A Translation and an Appraisal of De Docta Ignorantia. Translated by Jasper Hopkins. Minneapolis: Arthur J. Banning Press.
Sahagún, Bernardino de. 1961. Florentine Codex: General History of the Things of New Spain. Book 6, Rhetoric and Moral Philosophy. Edited and translated by Arthur J. O. Anderson and Charles E. Dibble. Santa Fe, NM, and Salt Lake City: School of American Research and University of Utah.
Sor Juana Inés de la Cruz. 1951. Obras completas. Vol. 1, Lírica personal. Edited by Alfonso Méndez Plancarte. Mexico City: Fondo de Cultura Económica.
Wittgenstein, Ludwig. 1922. Tractatus Logico-Philosophicus. Translated by C. K. Ogden. London: Kegan Paul, Trench, Trubner.
Studies
Idel, Moshe. 1988. Kabbalah: New Perspectives. New Haven, CT: Yale University Press.
Kostićová, Zuzana Marie. 2025. “Aztec Religion between Christianity and New Age Spirituality: ‘Mana’ and Spiritual Energies in James Maffie’s Concept of Teotl.” Numen 72 (2–3): 178–206.
León-Portilla, Miguel. 1963. Aztec Thought and Culture: A Study of the Ancient Nahuatl Mind. Translated by Jack Emory Davis. Norman: University of Oklahoma Press.
Maffie, James. 2002. “Why Care about Nezahualcoyotl?: Veritism and Nahua Philosophy.” Philosophy of the Social Sciences 32 (1): 71–91.
Maffie, James. 2014. Aztec Philosophy: Understanding a World in Motion. Boulder: University Press of Colorado.
Paz, Octavio. 1988. Sor Juana, or, The Traps of Faith. Translated by Margaret Sayers Peden. Cambridge, MA: Belknap Press of Harvard University Press. Originally published as Sor Juana Inés de la Cruz o Las trampas de la fe (Mexico City: Fondo de Cultura Económica, 1982).
Priest, Graham. 2002. Beyond the Limits of Thought. 2nd ed. Oxford: Clarendon Press.
Rescher, Nicholas. 2009. Unknowability: An Inquiry into the Limits of Knowledge. Lanham, MD: Lexington Books.
Sánchez Vázquez, Adolfo. 2002. “El ‘Sueño’ metódico de sor Juana.” Literatura Mexicana 13 (2): 49–63.
Scholem, Gershom. 1987. Origins of the Kabbalah. Edited by R. J. Zwi Werblowsky. Translated by Allan Arkush. Princeton, NJ: Princeton University Press.
Scholem, Gershom. 1995. Major Trends in Jewish Mysticism. New York: Schocken Books.
Volkow Fernández, Verónica. 2017. “Primero sueño de Sor Juana: una lectura anagógica.” Interpretatio: Revista de Hermenéutica 2 (2): 131–56.
