  Dingle’s article appeared back-to-back with an appraisal of kinematic relativity by the important American cosmologist H. P. Robertson (Robertson 1933a). Robertson focussed upon Milne’s hypothetico-deducivism as well, noting that the cosmological principle in kinematic relativity functions as an a priori rule, rather than as an empirical generalization, its status in relativistic cosmology. Robertson otherwise is not especially taken with Milne’s theory, limiting himself to remarks suggesting that, where they can be compared, kinematic relativity and relativistic cosmology apparently are similar in physical content. As we shall shortly see, Robertson’s later work strongly belied this earlier apparent indifference to Milne’s theory.