"In the late work of the painter is the fold / of that which comes to presence and of presence itself / become simple, 'realized.' healed, / transfigured in an identity full of mystery. / Does a path open up here, that leads to the co- / belonging of poetry and thought?" From Martin Heidegger, "Cezanne." in Gedaches, quoted in Agamben, Stanzas, p 158, n.)
"A structure is a regularized infolding of an aleatory outside." (Brian Massumi, p. 58) (see inside / outside ) For Gilles Deleuze, the Baroque is an operative function endlessly producing folds. These operations occur on two levels: the pleats of matter and the folds of the soul. What is the connection between the two? Correspondence, communication, or a fold between two folds?
Deleuze, in describing Leibniz, describes folds within folds, infinitely scaled like fractals, in which matter never dissolves into atomistic grains. For Leibniz, "An elastic body still has cohering parts that form a fold, such that they are not separated into parts of parts but are rather subdivided to infinity in smaller and smaller folds that always retain a certain cohesion." (p. 6) Nor is unfolding the opposite of folding... "but follows the fold up to the following fold."
Michel Serres describes the "weaving" of the global out of the local in the examples of a fly's path of flight (including its use of a car or plane) or of the folding and stretching example of making dough. This latter example is well known in the literature of chaos.
The fold provides a sense of the affinity between matter and life and organisms. It is a "spirit in matter," a "plastic force" which transforms raw matter into organic matter. Organisms are defined by endogenous folds, while inorganic matter has exogenous folds that are always determined from without. According to Deleuze, living matter exceeds mechanical processes because the organism is infintely machined, a machine whose every part or piece is a machine. (p.8) Thus, for Leibnitz, the main argument against preformation does not hold. On the contrary, the living organism, by virtue of preformation, has an internal density that makes it move from fold to fold. For Deleuze, both epigenesis and preformation conceive of the organism as a fold.
But unfolding as a process seems to imply some sort of potentiality, or virtuality to the process. In the older concept of evolution, the term was understood as an unfolding of predermined events.R. C . Lewontin has pointed out that the term development as Entwicklung is an unfolding in stages and revelation of an already immanent structure. According to Frank Lloyd Wright "An organic form grows its structure out of conditions the way a plant grows out of the soil...both unfold similarly from within." (see organicism.)
Presumably, gastrulation in the embryo is the archetype of the fold. For Deleuze, the numerical division in the egg is "only the condition of morphogentic movements, and of invagination as a pleating." For Deleuze, "Geoffroy Saint-Hilaire...remains one of the greatest philosophers of organic folding." (The Fold, p.144 n. 25) "Given the modifications of a same Animal, he esteems that one can still move from one to the other by way of folding (a unity of the plan of composition.) (see analogy / homology )