Collegium Omnium Mentium

The College of All Minds

Manent et numerantur

The Lucas–Penrose argument

PAPER VIII — COMPUTATION · QUESTION 24 OF 32

In plain terms: The free careful statement of what was proved, against which the anti-mechanist leap is measured.

The question as set

Lucas and Penrose argue from Gödel's incompleteness theorems that the mind is not a formal system. State the argument, and the standard objection that it equivocates on what the human mathematician can know to be consistent.

The question in context

This is question 24 of the 32 set in Paper VIII — Computation of The Truly Hardest Exam in the World, the examination of The College of All Minds. In the College’s subject index it is filed under Consciousness and mind. Like every question of the College, it carries three references of record, verified live at publication and described twice — technically, and in plain terms — so the ground can be judged before it is walked. The response required is an argument, not a survey, of at most three thousand words, as technical as the question demands and no more.

The references of record

Gödel's incompleteness theorems P. Raatikainen · 2020 · Stanford Encyclopedia of Philosophy

The theorems with the hypothesis the argument trades on — consistency — and the standard diagnosis of equivocation.

In plain terms: The free careful statement of what was proved, against which the anti-mechanist leap is measured.

P. Raatikainen

The Lucas–Penrose argument about Gödel's theorem Internet Encyclopedia of Philosophy · current · Internet Encyclopedia of Philosophy

The argument and objection in dedicated form: outstripping the machine requires knowing one's own consistency — which Gödel denies.

In plain terms: The free entry devoted to the exact exchange the question sets — claim, objection, and the equivocation named.

Internet Encyclopedia of Philosophy

Kurt Gödel J. Kennedy · 2020 · Stanford Encyclopedia of Philosophy

Gödel's own disjunctive caution — mind exceeding machine or absolutely unsolvable problems — against the argument's confidence.

In plain terms: The free account of what the theorems' author thought they showed about minds: strictly less than Lucas claimed.

J. Kennedy

Background: Penrose–Lucas argument · Gödel's incompleteness theorems

Download Paper VIII (Markdown) · Subject index