  To begin with, the cosmological thinking of the majority of scientists—including Eddington, de Sitter, Robertson, Tolman, and their colleagues—had betrayed a relatively unexamined, and apparently uncontroversial cluster of philosophical perspectives: on the metaphysical side they held a modest sort of explanatory realism—if an accepted theory referred to entity x, then x was acceptable as a genuinely, physically real object; to this metaphysical stance was coupled a methodology exhibiting a classic sort of inductive empiricism—scientific knowledge consisted of generalizations built up from individual empirical observations. But this cluster of views did not go long unchallenged. In early July 1932, just nine months after relativistic cosmology became the consensus during the British Association meeting, Oxford astrophysicist E. A. Milne published a short article in Nature which directly attacked the current philosophical tenets, proposing their replacement by a new cluster of views, one as radical as the new science it purported to undergird.