A subtle thought that is in error may yet give rise to fruitful inquiry that can establish truths of great value.

The remark captures a core Asimovian (and broadly scientific) attitude: even mistaken ideas can be intellectually productive if they are subtle enough to provoke careful testing, refinement, and debate. An error that is thoughtfully framed can function like a hypothesis—something to interrogate—leading investigators to clarify assumptions, improve methods, and sometimes discover unexpected truths. The quote also implies a distinction between crude falsehoods (which waste effort) and sophisticated errors (which can be generative). In this view, progress depends not on avoiding all mistakes, but on cultivating the kind of reasoning that turns mistakes into questions, and questions into knowledge.