I think that Latour’s AN INQUIRY INTO MODES OF EXISTENCE provides us with a host of categories other than object for describing what exists. In particular, the dynamic aspect of matter is described in Chapter 7 under the category MET or “the beings of metamorphosis”. Most of the chapter is focused on psychic entities, but at the end he remarks that these beings “precede the human, infinitely” (203). For me, calling all existents “objects” is already a reduction, and we need a more plural vocabulary.
On the question of the stability of objects, Latour has revealed that he found this problem particularly difficult. It was only after a conversation with Isabelle Stengers about Whitehead that he had an illumination that this stability was not universal, nor was it necessarily tied to humans. He conceived that it belonged to a specific mode of existence REP or reproduction, that ensures the persistence of beings.
Latour’s movement is to get away from the abstraction of the subject-object division and to come back to both historical and individual experience. On the basis of an ontological analysis of the phenomenology, he can then widen the import to more “cosmological” concerns. He makes it clear towards the end of the chapter we may consider that psychogenic metamorphosis is only one part of the metamorphic mode of existence: “Everything can, everything must, become something else” (203). So he elevates it to a cosmogenic principle on a par with reproduction.
On this model the beings of reproduction are prior to the bifurcation of subject and object, and so prior to, but at the basis of, the constitution of objects stricto sensu by means of human categorisation. The interplay between persistence and alteration, or reproduction and metamorphosis, is the “musical” substrate for all other modes of existence which modulate this rhythmic composition of process and stability: “they form the basso continuo without which no music would be audible” (204).