Full Idea
It is sometimes said that inductive reasoning is 'defeasible', meaning that considerations that support a given conclusion can be defeated by additional information.
Gist of Idea
Induction is 'defeasible', since additional information can invalidate it
Source
Gilbert Harman (Rationality [1995], 1.4.5)
Book Reference
Harman,Gilbert: 'Reasoning Meaning and Mind' [OUP 1999], p.31
A Reaction
True. The point is that being defeasible does not prevent such thinking from being rational. The rational part of it is to acknowledge that your conclusion is defeasible.