PT - JOURNAL ARTICLE AU - TI - On mathematical concepts of the material world DP - 1906 Mar 29 TA - Proceedings of the Royal Society of London. Series A PG - 290--291 VI - 77 IP - 517 4099 - http://rspa.royalsocietypublishing.org/content/77/517/290.short 4100 - http://rspa.royalsocietypublishing.org/content/77/517/290.full SO - Proc R Soc Lond A Math Phys Sci1906 Mar 29; 77 AB - The object of this memoir is to initiate the mathematical investigation of various possible ways of conceiving the nature of the Material World. In so far as its results are worked out in precise mathematical detail, the memoir is concerned with the possible relations to space of the ultimate entities which (in ordinary language) constitute the “stuff” in space. An abstract logical statement of this limited problem, in the form in which it is here conceived, is as follows:—Given a set of entities which form the field of a certain polyadic (i. e., many-termed) relation R. What “axioms” satisfied by R have as their consequence that the theorems of Euclidean Geometry are the expression of certain properties of the field of R? If the set of entities are themselves to be the set of points of the Euclidean Space, the problem, thus set, narrows itself down to the problem of the axioms of Euclidean Geometry. The solution of this narrower problem of the axioms of geometry is assumed (cf. Part II, Concept I) without proof in the form most convenient for this wider investigation. Poincaré has used language which might imply the belief that, with the proper definitions, Euclidean Geometry can be applied to express properties of the field of any polyadic relation whatever. His context, however, suggests that his thesis is, that in a certain sense (obvious to mathematicians) the Euclidean and certain other geometries are interchangeable, so that, if one can be applied, then each of the others can also be applied. Be that as it may, the problem here discussed is to find various formulations of axioms concerning R, from which, with appropriate definitions, the Euclidean Geometry issues as expressing properties of the field of R. In view of the existence of change in the Material World, the investigation has to be so conducted as to introduce, in its abstract form, the idea of time, and to provide for the definition of velocity and acceleration.