Ernest Nagel

C. D. BROAD once remarked that though inductive reasoning is the
glory of science, it is the scandal of philosophy. Whether or not this
characterization of philosophy is a merited one, there is no doubt that
despite substantial advances made by logicians and philosophical scien-
tists in the analysis of inductive arguments, even competent students
continue to disagree on many fundamental issues encountered in the sub-
ject. These issues include not only the notorious general problem of
"justifying" principles of inductive reasoning, but also special questions
concerning the formal logic and the methodology of inductive inference.
They run the gamut from doubts about the relevance of the mathematical
calculus of probability to the task of codifying the tacit rules governing
habitual inductive reasoning, through questions about the conditions
under which inductive arguments are valid and about the correct analy-
sis of the central notion of "the weight of evidence", to problems con-
cerning the epistemic status of generally accepted principles of inductive
inference. If it is a scandal to have unresolved issues, then the present
state of philosophic discussion on induction is indeed scandalous.

What is perhaps Carnap's most ambitious contribution to logical
analysis is his monumental but still incompleted attempt to put an end
to much of this scandal, if scandal it is. He has set himself the important
task of codifying the logic of induction, in a manner analogous to mod-
ern systematizations of deductive logic, and of doing this within the uni-
tary framework provided by a precise quantitative explication of the
basic idea of "the strength of evidential support". The foundations for
his system have been laid deep and in a characteristically meticulous
fashion; and though the structure is far from complete, its present out-
lines already exhibit the magnificent architectonic qualities of the com-
pleted design. Carnap employs his basic conceptions with brilliant in-
genuity, and he discusses mooted questions in the philosophy of induction
with flexible insight and with his usual candor. No students of the prob-
lems of inductive inference, whether or not they find themselves in
agreement with Carnap's approach, can fail to be instructed by the com-
prehensive analyses that support his system.

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