Making complex reasoning intelligible through maps you can check at every step
Ipsissima is for understanding writing that reasons to a conclusion — a philosophical argument, a legal judgment, a policy report. It breaks the argument down into individual steps, so you can see the conclusion you are being asked to accept, and the structure of the reasoning that supports it.
Ipsissima reads Argdown — the argumentation markup language created by Christian Voigt and maintained by the Argdown team — and opens an argument as an interactive map: the main claims at a glance, the detail where you choose to look, the marks a reader writes in the margin, and, when the map was drawn from a text, the passage each claim came from beside the claim that reports it. It runs entirely in your browser and makes no network requests of any kind. (The downloadable application speaks beyond your machine only when you choose Help ▸ Check for Updates, and can converse with Zotero on your own computer — showing your highlights, and storing the reconstruction under its source’s item with your permission — a conversation that never leaves it; the page on this site has nothing of the sort.)
The name is the distinctive half. ipsissima verba — the very words themselves, as against ipsissima vox, the authentic voice: did the author write these words, or is this a faithful report of what they meant? Every discipline that quotes anybody has had to draw that line — historians since Thucydides, jurists whenever quotation marks are at stake. Wherever a claim has a source to stand at a distance from, Ipsissima keeps the distinction, on every claim.
Try it now
One page, nothing to install. Drop an .argdown file onto it — or a whole folder, which brings
the manuscript with it so the claims can be laid out by where they appear in the text. Nothing
to open yet? The same panel can start a new one: a worked skeleton you replace claim by
claim, with the map redrawing as you write.
New to argument maps? Take the walkthrough: it is the first entry under How to use, runs on whatever you have open, and takes about two minutes.
There is also a read-only Reader, which is smaller and has no editor — the right one to send to somebody you want to show a reconstruction to.
Both pages carry the whole program, so they are a couple of megabytes and take a moment to arrive on a slow connection. Nothing is downloaded afterwards.
Or start from a worked example
Each opens a finished reconstruction with the text it was drawn from, so you can follow a claim back to the passage it came from and see how far it stands from the author’s own words.
Darwin, on natural selection
A single paragraph of the Origin, argued from variation and struggle to the conclusion those two earn. The smallest complete reconstruction here.
Carroll, What the Tortoise said to Achilles
The regress about rules of inference, reconstructed as a reductio the dialogue never states — with the imputation marked as the reconstructor’s own.
Miller v The Prime Minister [2019] UKSC 41
The prorogation judgment, mapped backwards from the order the court made. The steps the court needed to get there are its ratio; what it said by the way is marked obiter, and the authorities it rests on are marked as authorities.
James, The Will to Believe
The classic defence of the legitimacy of religious faith. Where a question is living, forced and momentous, and evidence cannot settle it, James argues that our passional nature not only may but must decide — against Clifford’s rule that believing on insufficient evidence is always, everywhere wrong.
Wilson, Williams, Dewey, and the Nature of Value Inquiry
A whole journal article, and the one that strains the method hardest: its argument moves like music rather than assertion, and the map ends in three contentions instead of one because forcing a single apex would mean inventing a claim the paper does not make.
Wilson, J. (2026) 'Williams, Dewey, and the Nature of Value Inquiry', Philosophy 101, pp. 511–538. Open access, reproduced by the author.
What it is for
A map of a text. A reconstruction of a paper, a judgment or a chapter is a scholarly claim about someone’s work, and it should be checkable like one. So every claim in the map records how far it stands from the words it came from — quotation, paraphrase, compression, interpretation, or the reconstructor’s own imputation — and every quotation is verified against the source, character for character, before the map is built. The border drawn around a claim tells you which it is. That makes two things visible that a normal argument map hides: whose words these are, and where the reconstructor has supplied something the author did not say.
Because each claim knows where it sits in the text, one map carries two views of the same claims: the structure of justification, in which everything is rearranged to show how it supports the conclusion, and the structure of exposition, which shows the claims in the order the text presents them. Switching between the two shows the rhetoric of a piece as well as its logic — how far the order of telling departs from the order of proving.
A map of a debate. Some arguments belong to no single text: the case for and against censorship, or a drug law, is a pattern of public argument, not a document. Ipsissima opens these maps too, and leaves out what does not apply — no manuscript pane, no source borders, just each standpoint’s case laid out step by step where anyone can examine it. Here there is nothing for the tool to check a claim against, and it does not pretend otherwise: a debate map stands on the fairness of the person who drew it, named in the map’s own front matter, and the tool’s job is to make every step visible enough to challenge.
A map of your own. Ipsissima is also an editor, and for most people the lightest way to write Argdown — one page in a browser, rather than a programmer’s IDE. Start a new map from the opening panel (File ▸ New in the application), write, and the map redraws as you go; where a line does not parse, the editor says so on the line, with the real Argdown parser doing the judging.
A map of a draft. Reconstruction does not have to wait for a finished text. If the argument of a paper or a chapter is not coalescing, tell Ipsissima-MCP — the reconstruction half, described below — that it is working from a draft: the map shows which parts of the argument are already solid and where the gaps are, while the writing can still respond.
The other half
Ipsissima-MCP turns a document
into something a reconstruction can cite — getting a PDF, EPUB, .docx or HTML article into
structured Markdown with its paragraphs and page numbers intact — and then checks the finished
reconstruction against its sources word for word. It is an MCP server, so you can ask an assistant
you are already talking to for an argument map and it does the rest.
It does not reconstruct arguments itself. That judgement belongs to the model, and the instructions given to it are served as a prompt read off disk, where anyone can read and change them.
On Claude Desktop it installs by double-clicking: take the .mcpb bundle from the
releases page and open it. You will need
Node on the machine; Claude Desktop provides the rest.
In a terminal it is one line: uvx ipsissima-mcp runs the released server straight from
PyPI — so
claude mcp add ipsissima -- uvx ipsissima-mcp is the whole install for Claude Code, and any
other MCP client points at the same command. Node is still needed.
Get the application
The desktop application adds what a web page cannot do: open a .argdown by double-clicking it,
save back in place, and reload the manuscript when it changes on disk. macOS, Windows and Linux
builds are on the releases page — the .dmg, the
-setup.exe, and the .deb or .AppImage respectively.
The builds are unsigned, so the first launch is blocked once, and the block looks worse than it is. On macOS: drag Ipsissima into Applications (choose Replace if you are updating), launch it from there, click Done on the warning, then allow it under System Settings → Privacy & Security → Open Anyway. On Windows: More info, then Run anyway. Installing Ipsissima shows every dialog before you meet it.
Ipsissima is by James Wilson, and stands on other people’s work: the Argdown language, created by Christian Voigt and maintained by the Argdown team; the reconstruction method of Alec Fisher and Trudy Govier; Tom Stern’s article on charity and quotation, which is why the checks do not stop at verbatim; and Gregor Betz and Georg Brun, who named the distinction this program draws before it drew it. CREDITS.md says it properly. The source is on GitHub. The samples above are public domain (Darwin, Carroll), Crown copyright reused under the Open Government Licence (Miller), or open access reproduced by their author (Wilson).