Charles Sanders Peirce · Philosophy
Peirce’s founding rule of pragmatism - that the whole meaning of any conception lies in its conceivable practical effects - and the three grades of clearness that lead up to it, grounded in his theory that a belief is a rule for action.
In 1878 Charles Sanders Peirce published ‘How to Make Our Ideas Clear,’ part of a series called Illustrations of the Logic of Science, and quietly launched a philosophical movement. His target was an old ideal of clear thinking inherited from Descartes and Leibniz. The logicians had recognized two grades of clearness in an idea. The first is mere familiarity: an idea is ‘clear’ when you recognize it and are not confused by it in ordinary life. The second is distinctness: an idea is distinct when you can give an abstract definition of it, spelling out its parts in words. Peirce thought both grades were feeble - the first is just a comfortable feeling that can accompany the haziest notion, and the second merely shuffles words into other words. He proposed a third and higher grade of clearness, and with it a rule for reaching it: to grasp a conception fully, trace out the conceivable practical effects the object of that conception would have. Those effects, and nothing else, are the whole of the conception’s meaning.
The maxim does not fall from the sky; Peirce derived it from a theory of what thought is for. Thought, he argued, exists to produce beliefs, and a belief is not a passive picture in the mind but a habit - a rule for action. To believe that fire burns is to be disposed to keep your hand out of the flame. Different beliefs are distinguished not by any inner glow but by the different actions they lead to; two supposed beliefs that would issue in exactly the same conduct in every situation are the same belief. From this it follows directly that the meaning of any thought is just the sum of the habits of action it would produce - and since action always bears on what affects the senses, the meaning of a conception must be statable in terms of conceivable sensible effects. The maxim is simply this insight turned into a working rule.
Peirce showed the maxim at work on concept after concept. To say a body has weight is to say that, in the absence of an opposing force, it would fall - again a conceivable practical effect. To grasp force, the great abstraction of physics, we need not hunt for a mysterious entity behind the motions; we need only lay out how force enters the calculation of accelerations, how it would show itself in the changes of bodies. Reach the third grade of clearness, and a whole class of apparently deep puzzles turns out to be about nothing at all, because the rival answers would make no conceivable difference to experience. The maxim is thus a razor for meaning: it does not tell us what is true, but it strips away pseudo-questions and forces every genuine idea to declare, in the coin of possible experience, exactly what it is worth.
This is the opening of the lesson. The rest — the dialogue, the primary source, and the recall — is in the app.
You learned that Peirce added a third, higher grade of clearness beyond ‘clear’ and ‘distinct’: trace a conception’s conceivable practical effects, because those effects are the whole of its meaning. Explain the maxim and why he tied the meaning of a thought to the habit of action it produces.
Leads to William James.
Begin this lesson →epoché — a humanities education that remembers you.