ABSTRACT
This chapter considers what has most often been meant by "argument from analogy". It also considers the factor upon which the strength of an argument from analogy depends. Aristotle's second use of the word is concerned with the enumeration of particular instances. From the consideration of each of the members of a limited class we may pass to a generalization concerning all the members of that class. The word "analogy" has been used in various senses. Every generalization must be based upon resemblance; hence, every generalization involves both analogy and enumeration. The chapter examines the characteristics upon which the strength of an analogical argument depends. Analogy in the widest sense is not a special form of argument but an element in all inductive investigation. The chapter shows that an induction by simple enumeration is possible only when the instances enumerated have common properties, and it is thus based upon analogy.
