one person's honest and forthright criticism is more valuable than the mindless compliance of a thousand people; literally, the 'yes yes' of a thousand people is not as good as the 'honest speech' of one scholar

Erwin Schrödinger (1887-1961), Austrian physicist and Nobel laureate known for his work in quantum mechanics

Schrödinger's wave equation in quantum mechanics

outspoken; frank and candid in speech; especially used in the context of officials giving honest advice to superiors

(literary) outspoken; honest and straightforward in speech