The book was written in the aftermath of the Sokal hoax and the broader 'science wars' that pitted scientific realists against scholars in science studies, cultural studies, and critical theory. Latour was a particular target of the realists, who accused him of dissolving scientific facts into social construction. His reply, developed across the essays, was that neither 'construction' nor 'fact' named what actually happens in scientific practice. Facts are constructed — that is, produced through concrete chains of laboratory work, instrumentation, and institutional stabilization — and they are also real, in the sense that they refer to features of the world that do not reduce to the social processes that produce the knowledge.
The book's most influential essay for technology theory is 'On Technical Mediation,' which develops a four-part analysis of how tools modify the actors that use them. Latour traces the gun-control debate — 'guns don't kill people, people kill people' versus 'guns kill people' — to argue that both sides are wrong. Neither the gun alone nor the person alone explains what happens when a gun is fired. What explains is the hybrid: the person-with-gun, an actor-network whose capabilities, intentions, and consequences cannot be attributed to either party in isolation. The analysis generalizes to every technology, including AI.
For AI, the implications are direct. Claude does not passively transmit the human user's intention (the 'tool' view). Claude does not determine the outcomes independently of the human (the 'autonomous AI' view). What produces outcomes is the hybrid: the human-with-Claude, an actor-network whose capabilities are jointly constituted. The amplifier metaphor maps onto the failed 'guns don't kill people' position; it attributes all agency to the human and treats the technology as passive. The accurate description is hybrid: outcomes emerge from the combined action of human and AI within a network that includes both and neither alone.
The book also introduces the concept of 'circulating reference' — the chains of translation through which scientific claims connect to the phenomena they describe. A geological claim about the forests of the Amazon is supported by a chain that runs through soil samples, color charts, field notes, published diagrams, and expert testimony. No single link in the chain has direct access to 'nature'; but the chain as a whole produces reliable knowledge about the forest. The same structure applies to AI outputs: no single moment in Claude's processing provides direct access to the truth, but the chain of training, prompting, verification, and correction can produce reliable results — provided the chain is maintained.
The book collected essays Latour had written throughout the 1990s in response to the science wars and to ongoing philosophical debates about realism, construction, and the authority of science. It was published by Harvard in 1999 and became one of his most accessible works, frequently used in graduate seminars on science studies.
Its reception was significant in repositioning Latour as a defender of scientific realism against the more radical versions of social constructionism with which he had sometimes been conflated. The repositioning did not fully convince his critics, but it established clearer philosophical ground for ANT than had been available in the earlier laboratory studies.
Non-reductive realism. Scientific knowledge is about reality, but the access to reality is mediated by heterogeneous networks that cannot be reduced to either 'the social' or 'the natural.'
Technical mediation. Tools transform the actors that use them. The hybrid — actor-with-tool — is the proper unit of analysis, not actor or tool alone.
The gun essay. Gun-control debates are a paradigm case for analyzing how agency is distributed in person-tool assemblages. Neither 'guns don't kill people' nor 'guns kill people' captures the hybrid reality.
Circulating reference. Scientific claims connect to the world through chains of translation. No single link provides direct access; the chain as a whole produces reliability.
Factishes. Latour's portmanteau for entities that are simultaneously fabricated and real — facts whose constructedness does not diminish their truth-claims.