An actant is a material entity or human person or group that takes on form, definition, facticity — and, ultimately, agency — only to the extent that (1) it enters into an alliance with a spokesperson (as Marx would put it, actants “could not represent themselves; they had to be represented”), and (2) the resulting alliance is able to withstand “trials of strength,” including hostile attacks that are designed to bring about its dissolution. First used by Bruno Latour, the term is one of the central concepts of Actor-network theory (ANT).

To illustrate this concept, Latour (1987)provides examples of human and non-human actants:

  • A group of workers can be seen as an actant when a union representative tells management, “They are 100% in agreement that wages must increase by 10 percent.” Management may attack this by surveying the workers; if it turns out that nearly all of them really are insisting on a 10% raise, the alliance will have withstood its trial of strength.
  • Microbes can be seen as an actant when Pasteur tells France, “These are the cause of infections.” Other scientists attacked this by trying to break the connection. But they could not do so.

This is surely one of the most confusing of Latour’s concepts, and it is commonly thought that, in trying to restore a measure of material agency to science studies, Latour has lapsed into naive realism. But Latour strongly denies this. His reason for doing so is elucidated by placing his use of the actant concept in its broader context. As will be seen, Latour drew the actant concept from semiotics, and subsequently infused it with a good deal of Leibnitzian monadism. In addition, Latour’s use of the actant concept is the key element in his rejection of the social reductionism he sees in the Strong Programme, which was (and, arguably, still is) the most influential theoretical paradigm in S&TS. As will be seen, those who accept Latour’s work see the actant concept (and all that follows from it) as a significant intellectual advance; his critics see it as a shallow maneuver.

The concept of actant in semiotics

Drawing on the work of Russian folklorist V. Propp (Propp, 1986), A.J. Greimas observed that stories are constructed from a store of idealized characters called actants, such as the “sender” or “helper,” which are highly abstract and lack definition until they are revealed within the context of the story (Sonne and Grambye, 2006); an actant is “that which accomplishes or undergoes an act, independently of all other determinations” Greimas & Courtés, 1982:5, cited in Høstaker 2006). Acting as the spokesperson for these generalized or idealized characters, the author transforms them into actors (specific characters).

Following Sausserian linguistics, Greimas defines actants by their properties along three axes of differentiae: the conflict (helper and opponent), project (subject and object), and communication (sender & receiver) axes. This framework provides the reader with an intuitive grasp of a story’s potential such that characters, when they appear, reveal themselves to be one sort of actant or another, or (sometimes) a combination of two or more actants. As Høstaker (2006) helpfully explains, the overall “primitive” narrative formulation of a fairy tale looks like this:

1. The subject lacks a certain object (understood in wide terms). In the folktale the object might be person or thing missing after a misdeed by a villain.

2. The sender passes a contract with the receiver in order to liquidate the lack. In the folktale the sender is often a person from the social hierarchy (queen, king, mother, father) giving the receiver an obligation.

3. The subject, with or without a helper, accomplishes to obtain the object. This act may take the form of a combat with an opponent (or anti-subject). This is the test.

The influence of Greimas’ semiotics seems clear in the following (Latour, 1987:89-90, emphasis ours):

The ‘things’ behind the scientific texts are thus similar to the heroes of the stories we saw at the end of Chapter 1: they are all defined by their performances. Some in fairy tales defeat the ugliest seven-headed dragons or against all odds they save the king’s daughter; others inside laboratories resist precipitation or they triumph over bismuth…. At first, there is no other way to know the essence of the hero. This does not last long however, because each performance presupposes a competence which restrospectively explains why the hero withstood all the ordeals. The hero is no longer a score list of actions; he, she or it is an essence­ slowly unveiled through each of his, her or its manifestations …. It is clear by now to the reader why I introduced the word ‘actant’ e­arlier to describe what the spokesperson represents. Behind the texts, behind the instruments, inside the laboratory, we do not have Nature – not yet, the reader will have to wait for the next part. What we have is an array allowing new extreme constraints to be imposed on ‘something’. This ‘something’ is progressively shaped by its re-actions to these conditions. This is what is behind all the arguments we have analyzed this far.

Consider, too, the following:

  • “An actor is an actant endowed with a character” (Latour and Akrich, 1994).
  • Spokespersons make actors out of actants, “whom they endow with qualities, to whom they give a past, to whom they attribute motivations, visions, goals, targets, and desires, and whose margin of maneuver they define” (Latour, 1996a: 163).

The actant concept in context

In developing the actant concept, Latour signaled his break with the Strong Programme in the sociology of scientific knowledge (SSK), which was at the time (and arguably still is) the dominant theoretical paradigm in S&TS. In brief, the Strong Programme seeks sociological explanations for successful as well as unsuccessful scientific beliefs. The Strong Programme does not deny that “nature”– specifically manifested as a laboratory’s capacity to produce certain effects when a certain procedure is followed — plays a role in the outcome of scientific controversies; however, the Strong Programme’s methodology calls for the observer to suspend belief in the material determination of scientific outcomes. It is only then that the sociological component comes into view.

As Latour reflected on his study of Roger Guillemin’s biomedical laboratory, chronicled in Laboratory Life (Latour and Woolgar, 1986), it seems clear that he was reluctant to explain the successful outcome of the lab’s activities in purely social terms. What Latour actually saw was a group of talented, experienced researchers who repeatedly encountered anomalous and heretofore unknown entities, each of which was subject to multiple, conflicting explanations. Much of the researchers’ time was spent sorting out whether these entities were, in fact, mere artifacts. They therefore subjected these entities to “trials of strength,” for example, by freezing them, pounding them, mixing them with this and that, etc. In the end, something emerges that is defined only by its proven characteristics.

At the same time, Latour just as clearly wanted to avoid falling into the trap of reasserting naive realism; indeed, in Laboratory Life, Latour and Woolgar deny that the outcome of a scientific controversy can be explained by reference to the deciding role of nature or “truth.”

This is precisely why the actant concept is so fundamental to Latour’s take on science studies — especially after Latour infuses a good deal of Leibnitzian metaphysics into the idea. In Latour’s view, an actant is a monad in the way Leibnitz defined it: an indivisible, “windowless” entity that provides no privileged viewpoint. To put this point another way, an actant cannot be said to be natural (which is how scientists see it) or social (which is how Strong Programme scholars see it), because nature and society are the result of the process (e.g., science in the making) by which an actant becomes an actor. It is therefore impossible to explain the construction of “nature” by reference to “social” causes, since both “nature” and “society” are the consequences of a certain type of activity that we call science.

Latour’s semiotic maneuver enables him, at least in his view, to bring in a degree of material agency without lapsing into naive realism while, at the same time, he can give a voice to material agency without lapsing into sociological reductionism. It also serves as the foundation for the rest of his intellectual career, in which he has consistently elaborated and extended his notion of society consisting of a Parliament of things, in which various groups compete in an effort to serve as spokespersons for a range of actants.


Latour is arguing, essentially, that science studies is concerned with the actual processes by which nature and society are constructed, but this presumes a radical monadism in which neither can be said to exist at the start of a laboratory experiment. For Latour, this is “obvious,” but his critics strongly disagree; indeed, this assertion can be easily refuted: it is preposterous to say that nature and society have not been differentiated when the laboratory work begins. To be sure, one could arguably make this case for work as pioneering as the La Jolla lab that Latour studied — after all, Roger Guillemin, the lab’s director, won the Nobel Prize for the work Latour observed. Even granting Latour some latitude here — monadism makes some sense when you’re talking about a previously unknown entity — it tells us very little about the less-than-heroic, sub-Nobel Prize science that goes on in most scientific laboratories. The same goes for Latour’s account of what happens to the human/material hybrids after the leave the laboratory; in Latour’s view, these hybrids form alliances that are fundamentally based, again, on their ability to withstand “trials of strength,” and he shows no interest in understanding the outcome of such processes in social or political terms. Haraway sums up the objections to this remarkably apolitical view in the following terms: “it is less epistemologically, politically, and emotionally powerful to see that that there are startling hybrids of the human and non-human in technoscience… than to ask for whom and how these hybrids work” (Haraway, 1997: 280). All too often, trials of strength are set up with unfair rules from the get-go, and it seems that Latour’s epistemological commitments leave him unable to acknowledge that this is so.

Linguistic note: Why “-ant” and not “-ent?”?

In English, the suffixes -ent and -ant are derived, respectively, from Latin and French, and are generally used to form adjectives, as in confident, protestant, errant, etc. However, some F words with this suffix are used to describe a “material agent: coefficient, current, ingredient, secant, tangent, torrent; esp. in Medicine, as aperient, astringent, emollient, expectorant” (Oxford English Dcctionary, 2nd ed).