Counter-example

Counter-example designatesa single instance that refutes a general claim by contradicting it: if a claim asserts 'all X are Y', one X that is not Y shows it false — or at least not precise enough. It targets another claim and withdraws its generality.

It is itself challenged on two grounds: whether the instance is real (is Einstein actually smart?) and whether it truly falls under the claim (is Einstein one of 'all people'?). A sound counter-example forces the target to narrow, qualify, or be withdrawn.