What the subcontinent knew, how it knew it, and how we know that it did. Fourteen self-contained tutorials covering the corpus and its philosophy, the foundational sciences of language, number and method, and the applied work in mathematics, astronomy, metallurgy, engineering, architecture, medicine and government.
No background is assumed. Sanskrit appears in IAST with Devanāgarī alongside, and every technical term is explained where it first occurs. Each chapter ends with a self-check and a glossary.
What the phrase actually names. The shape of the corpus, the fourteen seats of learning, how a whole civilisation's technical knowledge was packaged to survive in human memory — and how to read claims about it responsibly.
Chapter 2Four collections, four priests, one altar. The internal layering of each Veda, what survived of the recensions and what did not, and the six auxiliary sciences built to protect the text — phonetics, grammar, etymology, metre, procedure and astronomy.
Chapter 3Ten systems of Indian philosophy — what each is actually trying to say, how they argue with one another, and where they end up. The six Vedic darśanas and the four non-Vedic ones, with a chronology and six axes of dispute.
Chapter 4Half a million verses of accumulated judgment. The encyclopaedic Purāṇas and what is buried in them; the two epics and their opposed methods; and the nīti literature that compresses practical wisdom into single memorable verses.
Pāṇini's Aṣṭādhyāyī taken apart mechanism by mechanism: the fourteen sound-strings, the abbreviation scheme that compresses 280 phonological classes into two syllables each, a word derived by hand, recursion in compounding, and the kāraka theory of sentence roles.
Chapter 6Decimal place value and zero, and the route they travelled to Europe. Names for numbers up to 1017 and beyond, two systems for encoding numbers as words, the ladders of length, time and weight — and a treatise on poetry that invented binary.
Chapter 7How the tradition decided what counts as knowing. Vaiśeṣika's inventory of what there is, the four legitimate routes to knowledge, the five-step inference, the six modes of debate — honest and otherwise — and the named fallacies.
From rope geometry and altar construction to the Kerala school's infinite series. Algorithms for squaring and root extraction worked through in full, the pulveriser and the cyclic method, combinatorics from prosody, magic squares, and the origin of the word “sine”.
Chapter 9Āryabhaṭa's planetary parameters computed out and set beside modern values — the sidereal day to a hundredth of a second, Saturn out by a week. Plus the nakṣatra system, the five kinds of year, the pañcāṅga worked by hand, and Jai Singh's masonry instruments.
Chapter 10Wootz crucible steel and why Europe could not copy it. Why zinc cannot be smelted like any other metal, and the downward distillation that solves it. The iron pillars, a thirteenth-century classification of iron–carbon alloys, and lost-wax casting.
Chapter 11Dams still in service after nineteen centuries, stepwells, wall-plaster recipes with a stated hundred-year guarantee, perfumery as eight named unit operations, Suśruta's surgery — and a ship table in which every sea-going hull has a beam of exactly one-eighth its length.
Chapter 12Architecture as a design method rather than a style: a modular grid spanning four orders of magnitude, eight standard town plans each with a stated purpose, a four-grade professional hierarchy, a road hierarchy with fixed widths, and the anatomy of a temple.
A definition of health that requires mental wellbeing, from roughly two thousand years before the WHO adopted one. The three doṣas and seven tissues, Caraka's nine-cell aetiology of disease, the daily regimen, diagnosis, pañcakarma, and the eight limbs of yoga.
Chapter 14The Arthaśāstra as an operating manual for a state: seven constituents in order of importance, the ruler's day in sixteen periods, seven heads of revenue and a thirty-term tax glossary, panels of three judges at four levels, and thirty-odd departments of government.
Chapter 3 introduces ten systems in a single page. Two further tiers go under it: a full page for each of the ten darśanas, and — beneath Vedānta — a page for each of its eight schools.
All the systems at once: what each is trying to say, how they argue with one another, a chronology, and six axes on which they divide. Start here.
Tier 2 · ten pagesOne page per system, in its own vocabulary: the root text, the technical machinery, the arguments made and the arguments taken, and what survives of it.
Tier 3 · eight pagesOne canon, eight incompatible readings of it. A comparison matrix, the tat tvam asi reading test applied side by side, and a page for each school on its own terms.
A place to dive inSuperimposition, the indeterminable, three grades of reality, the two brahmans, and liberation as the removal of an error that was never a fact — with the seven objections it had to answer.
Nothing is repeated. Tier 1 states the positions and the disagreements; tier 2 assumes you have read it and goes into each system's own technical apparatus; tier 3 assumes tier 2's Vedānta page and takes the eight schools separately. Each page links up and down, and each is self-contained enough to be read alone if you would rather not start at the top.
Every page and every section on this site, nested the way the site is nested. Open a branch to see inside it; click any line to go straight there.
The filter searches all of it at once — section headings and their Sanskrit, plus what each section actually contains: the subject of every figure, the title of every callout, the open questions, and all 500-odd glossary terms. Try apoha, wootz, kaṭapayādi, marma or vyāpti. Where a match is not in the heading, the line says what it matched.
These pages try to hold a line between two failure modes: assuming in advance that a pre-modern Indian text cannot contain a real result, and reading modern physics into a metaphor. Where a claim is established, it is stated plainly. Where it is contested — most dates before about 500 CE, the transmission of Kerala mathematics to Europe, the safety of metallic preparations — the disagreement is described rather than resolved.
Chapter 1, section 11, sets out the four questions worth asking of any claim in this field. They were applied throughout.
Every diagram is hand-drawn inline SVG — no third-party images, no image files, no analytics, and nothing loaded from any server except two Google fonts. The pages work offline once cached, print cleanly, and read correctly on a phone.
All fourteen share assets/iks.css and assets/iks.js; chapter 3 is self-contained. Interactive elements (tabs, self-check questions, diagram highlighting) are progressive enhancements — the content is complete with JavaScript disabled.
Coverage follows the standard fourteen-chapter syllabus of the Indian Knowledge Systems course. Primary texts are cited by chapter and verse where quoted. Secondary sources are named in each chapter's footer; those used most are the Indian National Science Academy's History of Technology in India, Datta and Singh's History of Hindu Mathematics, Ifrah's Universal History of Numbers, Rangarajan's and Shamasastry's Arthaśāstra, and Ranganathan and Srinivasan on wootz steel.
Numerical results that could be checked — Āryabhaṭa's planetary periods, the sidereal-day closure of the Bhāgavata time ladder, Mādhava's value of π, the magic-square constructions, the ship proportions, the marma count — were recomputed rather than copied.