"Whyte showed how at the core of Newtonian physics lies the assumption that the elementary processes of nature are reversible, or would be if they could be isolated, and hence in the system of Natural Philosophy time would not appear as an explicit factor. ...In the cosmological theories of Einstein, de Sitter and Lamaître new ideas were introduced concerning the character of universal space, but no corresponding advance was made in connection with the idea of time, except in so far as the idea of expansion pointed to a finite rather than an infinite past."