Each stratum, or articulation, consists of coded milieus and formed substances. Forms and substances, codes and milieus are not really distinct. They are the abstract components of every articulation. [TP: 501]
The materials furnished by the substratum constitute an exterior milieu for the elements and compounds of the stratum under consideration [TP: 49]
[But the materials] are not exterior to the stratum. The elements and compounds constitute an interior of the stratum, just as the materials constitute an exterior of the stratum; both belong to the stratum, the latter because they are materials that have been furnished to the stratum and selected for it, the former because they are formed from the materials. [TP: 49]
Once again, this exterior and interior are relative; they exist only through their exchanges and therefore only by virtue of the stratum responsible for the relation between them. [TP: 49]
Associated milieus imply sources of energy different from alimentary materials. . . . Obtaining an energy source permits an increase in the number of materials that can be transformed into elements and compounds. [TP: 51]
The associated milieu is thus defined by the capture of energy sources (respiration in the most general sense), by the discernment of materials, the sensing of their presence or absence (perception), and by the fabrication or nonfabrication of the corresponding compounds (response, reaction). [TP: 51]
The unforgettable associated world of the Tick, defined by its gravitational energy of falling, its olfactory characteristic of perceiving sweat, and its active characteristic of latching on: the tick climbs a branch and drops onto a passing mammal it has recognized by smell, then latches onto its skin (an associated world composed of three factors, and no more). [TP: 51]
Active and perceptive characterstics are themselves something of a double pincer, a double articulation. [TP: 51]
Milieus always act, through selection, on entire organisms, the forms of which depend on codes those milieus sanction indirectly. [TP: 52]