Recent Articles

Jon Awbrey

Have Logic, Will Travel

Knol Thyself


Theory of Signs

“Semeiotic” is a term used by Charles Sanders Peirce that serves to distinguish his theory of triadic sign relations from other approaches to the same subject matter, more generally referred to as “semiotics”.

Logical Graphs : 2

Formal Development

Logical graphs are next presented as a formal system by going back to the initial elements and developing their consequences in a systematic manner.

Praeclarum Theorema

The “Splendid Theorem” of Leibniz

The praeclarum theorema, or splendid theorem, is a theorem of propositional calculus that was noted and named by G.W. Leibniz.

Hypostatic Abstraction

The Care and Breeding of Abstract Objects

Hypostatic Abstraction (HA) is a formal operation on a subject–predicate form that preserves its information while introducing a new subject and upping the “arity” of its predicate. To cite a notorious example, HA turns “Opium is drowsifying” into “Opium has dormitive virtue”.

Peirce’s Law

A Curious Truth of Classical Logic

Peirce’s law is a logical proposition that states a non-obvious truth of classical logic and affords a novel way of defining classical propositional calculus.

Logic of Relatives

Relations Via Relative Terms

The logic of relatives, more precisely, the logic of relative terms, is the study of relations as represented in symbolic forms known as “rhemes”, “rhemata”, or “relative terms”.

Differential Logic

The Logic of Change and Difference

Differential logic is the logic of variation — the logic of change and difference.

Logical Graphs : 1

Moving Pictures of Thought

A logical graph is a graph-theoretic structure in one of the styles of graphical syntax that Charles Sanders Peirce developed for logic.