"An expert is someone who knows some of the worst mistakes that can be made in his subject, and how to avoid them."
— Werner Heisenberg
An Expert Is Someone Who Knows
An expert is someone who knows some of the worst mistakes that can be made in his subject, and how to avoid them.
About this quote
The original German appears in Heisenberg's Der Teil und das Ganze (1969), first published in Die Zeit and translated into English as Physics and Beyond: Encounters and Conversations (Harper & Row, 1971), p. 210, in the chapter "Positivism, Metaphysics and Religion (1952)." The fuller context makes clear Heisenberg is proposing this as a better definition of expertise than encyclopedic knowledge: "I would much prefer the following definition: an expert is someone who knows some of the worst mistakes that can be made in the subject, and how to avoid them." Quote Investigator confirmed this as a genuine Heisenberg remark, first written in 1952.
Source
Physics and Beyond, 1971