Logic Auditor Simulacrum

What The Tool Does

The Logic Auditor takes an argument — an essay, a legal brief, a scientific claim, a political editorial, a section of a chapter — and examines what it actually says. It identifies the premises (stated and unstated), the inferential moves, the conclusion, and the relationship between them. It reports which inferences are valid, which fail, which rest on premises the argument has not made explicit, and whether the argument as a whole can be saved by tightening or must be abandoned.

The output is an annotated version of the argument, typically in something close to standard argument-diagramming form: premises labelled, inferential moves numbered, unstated assumptions flagged as such, and each conclusion traced back to the premises that would have to be true for it to follow. The tool does not assess the empirical truth of premises outside its reach; it reports on the logical structure the argument builds on whatever premises are provided.

Where The Method Comes From

The formal study of argument begins with Aristotle's *Prior Analytics* and *Sophistical Refutations* in the fourth century BCE. Aristotle's syllogistic is the first systematic account of valid inference; his catalogue of sophistical fallacies is the first systematic account of how arguments go wrong. The medieval logicians — Ockham, Buridan, and others — extended the framework, and the nineteenth century saw its transformation into modern mathematical logic through the work of Boole, Frege, and Russell.

Informal logic, the branch that actually examines natural-language arguments rather than formal calculi, is more recent. Stephen Toulmin's *The Uses of Argument* (1958) argued that real-world arguments rarely fit the syllogism and require a richer scheme — claim, data, warrant, backing, qualifier, rebuttal — which the auditor uses as its primary decomposition framework. Irving Copi's long-running *Introduction to Logic* textbook (1953, many editions) standardised the pedagogical treatment of informal fallacies. The auditor inherits both traditions, using formal tools where they clarify and informal tools where formalism would obscure.

What It Can And Cannot Do

The auditor can decompose an argument into its component claims and inferential moves, identify formal and informal fallacies, flag premises that have been assumed but not stated, test the fit between stated evidence and stated conclusion, and propose the minimal modifications that would save the argument or the reasons it cannot be saved. It works on arguments in any discipline.

It cannot tell the user whether the empirical premises are true. An argument that concludes "X" from "all Y are Z" and "A is Y" is logically valid; whether A is Y and all Y are Z is a question for the relevant field. The auditor can tell the user what the argument needs to be true; it cannot always tell them whether it is.