  He set forth a Realist philosophy on traditional empiricist principles: “He thought that practically everything was right out there where it belonged” (Firth, Nozick and Quine 1983, p 246). He maintained that while all knowledge of fact rests on perceptual experience, it is not limited to the perceptually given, but can be extended beyond that by legitimate inference (1934a). In this way his Realism can develop the breadth and depth required to do justice to all the scientific techniques which so far surpass mere perception.