According to Ernst Cassirer, Plato's philosophy recognizes two contrary forms of representation, one of which is valid for the realm of being and the other for the realm of becoming. (Individual and Cosmos, p.125)
For Cassirer, " Form thinking" belongs to being, while "causal thinking" belongs to becoming. But strict knowledge is only possible of the always-being. That which is becoming can only be described, if at all, in the language of myth. Or rather, myth is already familiar with both the question of the "what" and the question of the "whence." "It sees everything that it grasps (the world as well as the gods) under this double aspect." (The Problem of Form and the Problem of Cause, in The Logic of the Cultural Sciences, p. 87)
Socrates first discovered the concept, or eidos as the relation between the particular and the general and as a germ of a new meaning of the general question concerning being. This meaning emerged in its full purity when the Socratic eidos went on to unfold into the (transcendental) Platonic "Idea." (see transcendence / immanence ) For Plato, the soul is an intermediary between being and becoming.
The Aristotelian system seemed to promise a different reconciliation of the opposition between being and becoming. Unlike Plato and the thinkers of pure form, Aristotle wanted to restore becoming to its rightful place, because he was convinced that only in this way could philosophy be transformed from a mere theory of concepts into a theory of reality. Form and matter, being and becoming, must become correlative. The peculiarly Aristotelian concept of the formal cause originates from this fusion. (Cassirer)
"In nature we may successfully search for something that endures , and in nature we may regard becoming as if any phase of it were the "reason" of a later phase and the "consequence" of an earlier one. We may even go so far as to say: Nature is the one mediate object that obeys the postulates of the rational theory of becoming." Hans Driesch, History and Theory of Vitalism, p. 193.
"Freedom means that a stream, as it were, of undetermined becoming of a really creative character runs through the totality of individuals." (ibid. p. 238)
One of the central arguments of philosophical writings influenced by contemporary science is to favor becoming over being, or to call for a new resolution of the two.
Deleuze and Guattari seek a thought-in-becoming, which is entirely immanent, not to develop a general idea (model) that would stand out and above (transcend) the bodies its subsumes. They constantly stress becoming --becoming other, becoming animal etc. as qualitative change.
They reject a metaphysics of Being dependent upon representation. (see plane of immanence) and characterize becoming as intransitive, not having an object of production other than itself. "Reality makes and remakes itself, but it is never something made." (see also duration)
In describing nomad art, Deleuze and Guattari describe "a nomadic absolute, as a local integration moving from part to part in an infinite succession of linkages and changes in direction. It is an absolute that is one with becoming itself, with process." (Mille Plateaus, p 494)
Ilya Prigogine and Isabelle Stengers hope to reconcile being and becoming in theories of irreversible processes, whose system state is associated with being, but whose laws of temporal change are associated with becoming. (see Order Out of Chaos, p. 310) They too, rejct the identification of being with timelessness. (see time)