"It is a feature of our attitude towards nature that we pay great regard to that which is permanent; and for the same reason the creation of anything in the midst of a region is signalised by us as more worthy of remark than its entry in the orthodox manner through the boundary." Ref: [E] Sect. 64 p. 147.
[E] = Arthur A. Eddington, "The Mathematical Theory of Relativity" (2nd edition), Cambridge, 1924 (pre-ISBN).
(The success of thermodynamics) "... suggests striving for an ideal -- to show, not that the laws of nature come from a special construction of the ultimate basis of everything, but that the same laws of nature would prevail for the widest possible variety of structure of that basis." Ref: [E] sect. 47 p. 106.
[S] = Sokolnikoff, "Tensor Analysis" (2nd ed), Wiley, 1964 (pre-ISBN), sect 31 p. 78.