Nebraska Academy of Sciences


Date of this Version



Transactions of the Nebraska Academy of Sciences, vol. 5 (1978)


Copyright by the author.


In some arguments, premises and conclusions are so related that if the former are true, so, necessarily, are the latter. Arguments having this property are said to be valid; those which lack it are said to be invalid. Some invalid arguments are worthless, but others are not. Among the latter are many arguments used by scientists, such as the arguments by which laws are inferred from their instances. These arguments, one wants to say, do not guarantee the truth of their conclusions, but they nevertheless make them more probable. Though not valid, they are inductively strong. Thus there arises the idea of an inductive logic, a logic which would provide a method for determining inductive strength, just as deductive logic provides a method for determining validity.

An inductive logic, if one could be developed, would give insight into both the nature and the grounds of scientific inference. The principles of such a logic would be the principles in accordance with which scientific reasoning proceeds, and showing such principles to be logical would leave little doubt as to their justifiability. The motives for developing an inductive logic are thus clear. What is less clear is that such a logic is actually possible. In recent years there has been heated controversy on this point, with philosophers such as Carnap and Hempel defending inductive logic, and other philosophers, such as Popper, claiming that there can be no such thing. The purpose of this paper is to consider whether anything worthy of the name "inductive logic" could ever be developed.