[10] Along with Michel Callon, Madeleine Akrich, and John Law, Latour is one of the primary developers of actor–network theory (ANT), a constructionist approach influenced by the ethnomethodology of Harold Garfinkel, the generative semiotics of Algirdas Julien Greimas, and (more recently) the sociology of Émile Durkheim's rival Gabriel Tarde.

Latour developed an interest in anthropology, and undertook fieldwork in Ivory Coast, on behalf of ORSTOM, which resulted in a brief monograph on decolonization, race, and industrial relations.

In recent years he also served as one of the curators of successful art exhibitions at the Zentrum für Kunst und Medientechnologie in Karlsruhe, Germany, including "Iconoclash" (2002) and "Making Things Public" (2005).

Latour rose in importance[citation needed] following the 1979 publication of Laboratory Life: the Social Construction of Scientific Facts with co-author Steve Woolgar.

[9] This early work argued that naïve descriptions of the scientific method, in which theories stand or fall on the outcome of a single experiment, are inconsistent with actual laboratory practice.

Latour and Woolgar argued that, for untrained observers, the entire process resembles not an unbiased search for truth and accuracy but a mechanism for ignoring data that contradicts scientific orthodoxy.

Drawing on the work of Gaston Bachelard, they advance the notion that the objects of scientific study are socially constructed within the laboratory—that they cannot be attributed with an existence outside of the instruments that measure them and the minds that interpret them.

Latour's 1987 book Science in Action: How to Follow Scientists and Engineers through Society is one of the key texts of the sociology of scientific knowledge in which he famously wrote his Second Principle as follows: "Scientist and engineers speak in the name of new allies that they have shaped and enrolled; representatives among other representatives, they add these unexpected resources to tip the balance of force in their favor."

[33] Similarly, philosopher John Searle[34] argues that Latour's "extreme social constructivist" position is seriously flawed on several points, and furthermore has inadvertently "comical results".

After a research project examining the sociology of primatologists, Latour followed up the themes in Laboratory Life with Les Microbes: guerre et paix (published in English as The Pasteurization of France in 1988).

In it, he reviews the life and career of one of France's most famous scientists Louis Pasteur and his discovery of microbes, in the fashion of a political biography.

Aramis was to be an ideal urban transportation system based on private cars in constant motion and the elimination of unnecessary transfers.

The proposed system had custom-designed motors, sensors, controls, digital electronics, software and a major installation in southern Paris.

Latour uses a narrative, anecdotal approach in a number of the essays, describing his work with pedologists in the Amazon rainforest, the development of the pasteurization process, and the research of French atomic scientists at the outbreak of the Second World War.

In her review of Pandora's Hope, Katherine Pandora states: "[Latour's] writing can be stimulating, fresh and at times genuinely moving, but it can also display a distractingly mannered style in which a rococo zeal for compounding metaphors, examples, definitions and abstractions can frustrate even readers who approach his work with the best of intentions (notwithstanding the inclusion of a nine-page glossary of terms and liberal use of diagrams in an attempt to achieve the utmost clarity)".

As Katherine Pandora states in her review: "It is hard not to be caught up in the author's obvious delight in deploying a classic work from antiquity to bring current concerns into sharper focus, following along as he manages to leave the reader with the impression that the protagonists Socrates and Callicles are not only in dialogue with each other but with Latour as well.

"[47] Although Latour frames his discussion with a classical model, his examples of fraught political issues are all current and of continuing relevance: global warming, the spread of mad cow disease, and the carcinogenic effects of smoking are all mentioned at various points in Pandora's Hope.

[48] In a 2004 article,[49] Latour questioned the fundamental premises on which he had based most of his career, asking, "Was I wrong to participate in the invention of this field known as science studies?"

(p. 231) To regain focus and credibility, Latour argues that social critiques must embrace empiricism, to insist on the "cultivation of a stubbornly realist attitude – to speak like William James".

(p. 238–239) Social critics tend to use anti-fetishism against ideas they personally reject; to use "an unrepentant positivist" approach for fields of study they consider valuable; all the while thinking as "a perfectly healthy sturdy realist for what you really cherish."

(p. 241) The practical result of these approaches being taught to millions of students in elite universities for several decades is a widespread and influential "critical barbarity" that has—like a malign virus created by a "mad scientist"—thus far proven impossible to control.

Most troubling, Latour notes that critical ideas have been appropriated by those he describes as conspiracy theorists, including global warming deniers and the 9/11 Truth movement: "Maybe I am taking conspiracy theories too seriously, but I am worried to detect, in those mad mixtures of knee-jerk disbelief, punctilious demands for proofs, and free use of powerful explanation from the social neverland, many of the weapons of social critique."

(p. 230) The conclusion of the article is to argue for a positive framing of critique, to help understand how matters of concern can be supported rather than undermined: "The critic is not the one who lifts the rugs from under the feet of the naïve believers, but the one who offers the participants arenas in which to gather.

The critic is not the one who alternates haphazardly between antifetishism and positivism like the drunk iconoclast drawn by Goya, but the one for whom, if something is constructed, then it means it is fragile and thus in great need of care and caution."

He argues that researchers must give up the hope of fitting their actors into a structure or framework, but Latour believes the benefits of this sacrifice far outweigh the downsides: "Their complex metaphysics would at least be respected, their recalcitrance recognized, their objections deployed, their multiplicity accepted.

"[51] For Latour, to talk about metaphysics or ontology—what really is—means paying close empirical attention to the various, contradictory institutions and ideas that bring people together and inspire them to act.

In his reaction to research showing that the pharaoh Ramses II probably died of tuberculosis, Latour thought "How could he pass away due to a bacillus discovered by Koch in 1882?