During, Elie. "Durations and Simultaneities: Temporal Perspectives and Relativistic Time in Whitehead and Bergson." Handbook of Whiteheadian Process Thought Vol. II. Edited by Michel Weber and Will Desmond. Heusenstamm, Germany: Ontos Verlag, 2008. 259-278.

Abstract

In Duration and Simultaneity (1922), a critical examination of the philosophical implications of Einstein's relativity theory, Bergson describes CN as "an admirable book," "one of the most profound ever written on the philosophy of nature." When it comes to interpreting relativity theory, Bergson's own philosophical agenda bears striking resemblance to Whitehead's. Yet, in many respects their thought seems to unfold in opposite directions on the crucial issue of simultaneity. In the three books where he explicitly deals with the philosophical implications of relativity theory (namely, PNK, CN and R), Whitehead aims to reconstruct the basic concepts of the physical world in order to bridge the gap between abstract mathematical constructs and the realm of lived experience. Although Bergson shares a similar concern for what is simply given in sense awareness, he is more inclined to draw demarcation lines than to explain why scientific theories give us such an effective grip on the real. Accordingly, his views on simultaneity stand in sharp contrast with Whitehead's evolving characterization of the fact of temporal togetherness, from the early works on relativity theory to the doctrine of co-presence expounded in PR. Whitehead's guiding intuition is that giving becoming its proper place within a philosophy of nature requires a reformulation of classical temporal issues in spatio-temporal terms - a task which requires in turn the construction of a positive philosophical theory of "space-time" and the spatial embedding of temporal perspectives, as opposed to a mere metaphysical rephrasing of the mathematical structure of physical theories. His first step in this direction consists in assuming that time is primarily a "stratification of nature," in other words, that time cannot be a self-subsistent entity, but only a character of process. Related to this claim is the idea, emphasized from 1915 onwards, that time, (regardless of its ontological status as substantival or relational) is abstracted from a deeper unity of a spatio-temporal kind: "there can be no time apart from space, and no space apart from time" (CN 142). Absolute time is a "metaphysical monstrosity" (PNK 8); time (just like space) is "an abstraction from the passage of events" (CN 34; see 21, 29). Hence, what is actually given for sense-awareness must be something more fundamental: a "slab" of nature whose extensive properties may well translate into space and time, but which is in itself neither spatial nor temporal. The concept of simultaneity is organically linked with this primitive experience of the passage of nature. The second step (which Bergson never explicitly takes) consists in acknowledging the existence of infinitely many serial time orders describing the total creative advance of nature: "The various time-series each measure some aspect of the creative advance, and the whole bundle of them express all the properties of this advance" (RCN 178). The problem of simultaneity arises between this second step and the first, in conjunction with the relativization of simultaneity relations effected by Einstein's theory of relativity. If no meaning can be given to the idea of absolute simultaneity (a "now" valid for all places and perspectives), in what sense can distinct - if not disjoint - time-series be gathered in a "bundle?" How does the primitive experience of the whole of nature relate to this variety of  temporal perspectives? Whereas Bergson dismisses the simultaneity of distant events as an artificial construct in order to achieve a local resolution of the problem in strictly temporal terms. Whitehead's aim is to root the multi-threaded time-systems in a natural concept of simultaneity which does not reduce to the local simultaneity of coincident events or co-present flows. On this basis alone can the relativity of simultaneity appear as something more than a mere artifact of our methods of time measurement, while  still allowing the philosopher to recover the texture of the universe, if not a global view of it. "I maintain the old-fashioned belief in the fundamental character of simultaneity. But I adapt it to the novel outlook by the qualification that that meaning of simultaneity may be different in different individual experiences" (R 67). The following is an overview of the philosophical issues that converge on the concept of simultaneity in Whitehead's early period (up to SMW). It starts with a rough outline of some debates over contemporary physics over the status of the "now," and then proceeds to a comparative examination of various aspects of the simultaneity concept in Bergson's and Whitehead's writings on relativity. The concluding section focuses on on some implications of the understanding of simultaneity for the resolution of the famous "twins paradox."