Ethica

An interactive reader for Spinoza's Ethics, built with React and TypeScript. It presents the whole work in English, French and Latin and traces the geometric argument from passage to passage.

Live site: rdaum.github.io/ethica

What it does

• Reads Parts I-V in English (Elwes), French (Appuhn) or Latin, or any two side by side
• Also includes the Political Treatise in English (Gosset), French (Saisset) and Latin, linked to the Ethics where its editors give a reference
• Keeps the book's structure: definitions, axioms, propositions, proofs, corollaries and their proofs, notes, lemmas, postulates, prefaces and appendices
• Shows what each passage rests on and what rests on it, with shortest dependency paths you can follow step by step
• Searches within a part, across both languages
• Links directly to any part (#III), passage (#III.prop.6), chapter (#TP.II) or section (#TP.II.5), and works with the back button
• Works by keyboard alone and on small screens

Development

npm install
npm start

Command	Purpose
npm test	Unit and data integrity tests
npm run test:e2e	Browser tests (run npx playwright install chromium once first)
npm run typecheck	TypeScript
npm run lint	ESLint
npm run build	Production build into build/
npm run generate:corpus	Regenerate the Ethics data in public/ from the sources
npm run generate:french	Regenerate the French Ethics
npm run generate:political	Regenerate the Political Treatise, after downloading its English by hand
npm run deploy	Build and publish to GitHub Pages

CI runs all of these except deployment, and fails if regenerating the English corpus changes public/. It skips the Latin because that needs network access; generate-latin.mjs caches its downloads in .cache/latin/.

How it fits together

ethica.txt ──────► scripts/generate-corpus.mjs ──► public/ethica_N.xml
                            │                      public/ethica-logic.n3
                            └─ scripts/lib/citations.mjs

The Latin Library ► scripts/generate-latin.mjs ──► public/ethica_la_N.json

public/ ─────────► src/App.tsx ── reader state, loading, URL
                     ├─ components/BookView.tsx        the text
                     ├─ components/ReasoningPanel.tsx  analysis of a passage
                     └─ lib/analysisClient.ts ► workers/reasoningWorker.ts
                                                  └─ lib/analysis.ts, lib/inference.ts

Files in public/ are generated. Change the generators rather than editing them by hand.

Passages

Each passage has a stable id such as III.prop.27.corollary2.proof, shared by the XML, the Latin and the graph. A numbered proof like I.prop.11.proof2 is always a true alternate ("Another proof"); the proof of a corollary sits under that corollary.

Citations and dependencies

scripts/lib/citations.mjs is the only place citations are read from the text. The graph records them as cites, alongside the structural provedBy, hasCorollary, hasNote and partOf.

lib/inference.ts derives dependsUpon from these, and lib/analysis.ts walks it to find transitive dependencies and paths. Only demonstrative passages create dependencies: citations in notes, explanations, prefaces and appendices stay as references, because they can legitimately look ahead. Tests assert that the resulting graph has no cycles and that no demonstration depends on a later proposition.

Latin alignment

generate-latin.mjs walks the Latin in the order of the English passages. Generation fails if any Latin block is left unplaced, apart from a short reviewed list in the script.

French text

generate-french.mjs parses Appuhn's 1913 translation from French Wikisource into public/ethica_fr_N.json, keyed by the same passage IDs as the English. Run npm run generate:french -- --report to see the alignment, length ratios and possible transcription slips. Generation fails if a passage or label doesn't line up. Slips confirmed against the scan of the printed edition are corrected in the script.

Political Treatise

generate-political.mjs writes public/political_N.json and public/political-logic.n3, which the analysis worker loads alongside the Ethics graph. The English must first be downloaded by hand from the Constitution Society to .cache/political/poltreat.txt. The Latin comes from the Latin Wikisource API and the French from the French Wikisource API. All three number their 211 sections alike, and generation fails if they stop lining up.

Three kinds of link are kept apart:

• Spinoza's section references ("per Art. 4. Cap. 2.") become ethics:cites. They are read from both languages. Where they disagree, the Latin wins, through a short reviewed list in the script that fails generation if anything new appears.
• The editors' footnotes of 1861 and 1883 are the only source of references to specific passages of the Ethics, so they become ethics:editorCites and the panel labels them as the editors'. Spinoza's own text says only "in our Ethics", at I.5, II.1, II.24 and VII.6. II.24's link comes from Saisset alone.
• Dependencies are not derived from the treatise at all. Its sections count as non-demonstrative, so it adds nothing to the Ethics dependency chains.

Known gaps in the source text

The English source (Project Gutenberg #3800) differs from the Latin in a few places. The reader follows the source rather than supplying a translation:

• Missing from the English: the corollaries of II.xiii. and IV.l., and the proof of IV.lxxii. The reader shows these passages with a note in English, and their text in French and Latin. Their place in the citation graph comes from a short reviewed list in generate-corpus.mjs, read from the printed Latin and French.
• Citations without a target: II.xvii. note cites the same missing corollary of II.xiii. Two others, in the proofs of III.i. and III.xix., cite a corollary or note the proposition doesn't have. All three resolve to the proposition. node scripts/generate-corpus.mjs --report-citations lists them.
• Misprint: the proof of IV.i. prints "IV. iii." where the Latin has III.iv. The text is unchanged, and the graph follows the Latin.
• Political Treatise, English: this is a 1998 transcription that has not yet been compared with a scan of the 1883 edition. It misprints some references (II.15 has "Sec. 18" for 13). Its text is unchanged, and the graph follows the Latin.
• Political Treatise, French: Saisset's text on Wikisource is mostly uncorrected OCR, so the reader warns about it. Reading errors found so far are corrected against the scan, in a list in the script. Its transcription drops the text of 14 notes, which are restored from the scan. Other errors may remain.
• Political Treatise, Latin: the Wikisource page states no edition and has visible typing errors, such as "Sedi ne ii" in II.1. These are left as found. Its numbered note markers have no notes, so they are removed, and Chapter VIII's synopsis opens its first section.
• Typography: the source uses a long dash for ordinary hyphens, as in "self—caused". The generator hyphenates the compounds listed in scripts/lib/compounds.mjs and leaves every other dash as printed.

Dependency notes

• npm audit reports a moderate minimatch advisory. It is only reachable through ESLint, which runs on this repository's own files, and the production dependencies are clean. The suggested fix would downgrade ESLint to version 4, so it has not been applied.
• TypeScript stays on 5.9 until typescript-eslint supports version 7.

Project direction

SPINOZA_MARKUP_PROJECT.md separates what has been built from ideas for later.

Text attribution

The English is the translation by R.H.M. Elwes (1883) from Project Gutenberg #3800. The Latin is from The Latin Library. Both texts are in the public domain.

The Political Treatise is translated by A.H. Gosset and edited by R.H.M. Elwes (G. Bell, 1883), as transcribed by Jon Roland of the Constitution Society in 1998. Its Latin is from Latin Wikisource. Its French is Émile Saisset's translation (Charpentier, 1861), from French Wikisource.