People
I believe there is no source of deception in the investigation of nature which can compare with a fixed belief that certain kinds of phenomena are impossible.
— William James
Behind the line May contain spoilers.
Our reading
An editorial interpretation.
The speaker argues that the biggest trap when studying nature is deciding beforehand that some things can't happen. A fixed belief in impossibility distorts what you're willing to see, and so it deceives more powerfully than any other source of error.
Context reviewed