Ontological turns, turnoffs and roundabouts.

There has been much talk of an 'ontological turn' in Science and Technology Studies. This commentary explores some recent work on multiple and historical ontologies, especially articles published in this journal, against a background of constructivism. It can be tempting to read an ontological turn as based and promoting a version of perspectivism, but that is inadequate to the scholarly work and opens multiple ontologies to serious criticisms. Instead, we should read our ontological turn or turns as being about multiplicities of practices and the ways in which these practices shape the material world. Ontologies arise out of practices through which people engage with things; the practices are fundamental and the ontologies derivative. The purchase in this move comes from the elucidating power of the verbs that scholars use to analyze relations of practices and objects--which turn out to be specific cases of constructivist verbs. The difference between this ontological turn and constructivist work in Science and Technology Studies appears to be a matter of emphases found useful for different purposes.