Peter frederick strawson

The analytic reply

See Notes on Strawson on induction

13th November 2020

P.F. Strawson on Stanford Encyclopedia of Philosophy

A focus on the meaning of induction: the question of justification of the inductive method is wrongly posed itself. The belief in induction is not irrational.

To ask for a ‘justification’ of induction is to ask for a justification of induction in general, as a pattern of reasoning.
What’s at stake is whether induction as a whole is justifiable or justified.

It follows that to ask for a justification of induction in this sense is to ask for a proof that such logic process is actually viable.

Therefore, induction as such would need to be justifiable in one of two ways:

  • proving induction as a deductively valid process
    By satisfying this very demand, we would be making induction a deductive-based process itself.
  • Justifying induction with induction, which is absurd since its proof would be a never-ending cycle.

According to Strawson, the solution to this conundrum may be found at the roots of any attempt to justify induction.

Could we give another sense to this demand?
Can we try another solution?

Sometimes it is expressed in the form of a request for proof that induction is a reasonable or rational procedure, that we have good grounds for placing reliance upon it.


Reasonableness of the inductive procedure.

Unattainable proof

Rationality and justification of induction do not entail each other. Induction can be rational even if it’s not justifiable.

Induction is rational only if it can be justified Induction cannot be justified -------------- induction is not rational

It is an analytic proposition that it is reasonable to have a degree of belief in a statement which is proportional to the strength of the evidence in its favour; and it is an analytic proposition […] that other things being equal the evidence for a generalization is strong in proportion as the number of favourable instances, and the variety of circumstances in which they have been found is great. So to ask whether it is reasonable to place reliance on inductive procedures is like asking whether it is reasonable to proportion the degree of one’s convictions to the strength of the evidence. Doing this is what ‘being reasonable’ means in such a context.


Rationality of induction is accepted analytically, since rationality is part of the meaning of induction itself. There’s nothing else in the rationality of induction than having the

to what standards are we appealing when we ask whether the application of inductive standards


The demand for justification in induction happens because the two following statements are confused:

  1. [the universe is such that] induction will continue to be successful
  2. Induction is rational

  1. A posteriori, contingent statement
    we have no guarantee that this holds and will hold forever; this is an inductive statement itself.
  2. A priori, analytic statement
    the rationality of induction is not about how the world is and how it works, but about the very meaning of the term, and what we attribute to it.

Even if the world turned to be totally chaotic, induction would still be rational, by telling us not to rely on regularities or to form expectations. Even if statement 1 falls apart, statement 2 will continue to hold, since the latter does not depend on the former. Thus, justifying induction doesn’t condition its rationality.

Can we ultimately affirm that rationality is arbitrarily defined. Even if we do, we’re not entitled to question this: calling something rational doesn’t automatically make it rational.

Next topic: Karl Popper



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