Bertrand Russell Quotes 366
It follows that if physics is an empirical science, whose statements can be confirmed or confuted by observation, then physics must be supplemented by laws connecting stimulus and sensation. Now such laws belong to psychology. Therefore what is empirically verifiable is not pure physics in isolation, but physics plus a department of psychology. Psychology, accordingly, is an essential ingredient in every part of empirical science.
Source: Human Knowledge, 1948.
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