In drawing on the lexicon of amatory speech as empirical site for [REL], Bruno Latour seems to be inserting himself into a particular context of twentieth-century French thought that might be characterised as reflecting on the philosophical implications of love whilst at the same time engaging in a subterranean conversation with the theological (Christian) tradition that has appropriated it from Augustine onwards. One important (albeit non-avowed) interlocutor in this regard is Alain Badiou.
Both Badiou and Latour begin with an empirical description of love before ‘shifting up’ to a new plane of philosophical institution. The basic dynamic of that shifting up is as follows: the empirical description serves as an ethnographic or anthropological enquête sur terrain that is capable (when gently tapped by the philosopher’s hammer) of yielding the universal value that is properly housed in the institution. However, they shift up in different ways. A brief comparison of these two might therefore provide a useful context for drawing out what is particular to Latour’s concept of [REL].
To begin, then, what is Badiou’s understanding of the phenomenon of ‘love’ itself? In his wonderful little dialogue, In Praise of Love (2012), Badiou argues that the contemporary situation of love is characterised by existential conservatism (the reluctance to enter into a love relationship until it is ‘safe’ to do so) and regulated pleasure (the withdrawal of the commitment of the whole self from a love relationship once it has begun for fear of damage or rejection).
Contra this pernicious drift, Badiou argues that contemporary love must be re-invented. He seeks to do this by positing love as a fundamental truth procedure furnishing a universal ground by which (sexual) difference—what it means to be two and not one—can be thought:
I mean truth in relation to something quite precise: what kind of world does one see when one experiences it from the point of view of two and not one? What is the world like when it is experienced, developed and lived from the point of view of difference and not identity? (Badiou, In Praise of Love, 2012 , p.22)
For Badiou, then, before the encounter that inaugurates the amorous procedure, there would be nothing in the world but ‘monads’ or ‘ones’, each enclosed in its own narcissistic sphere. A declaration of love is a declaration that such solipsistic or narcissistic experience has been irruptively fractured. The unity that results, however, is not wholly or reductively fusional: Badiou describes it as a ‘scene of the Two’ that is affirming of two individuals who were and remain discrete (Badiou, Conditions, 2008 , p.181).
There are many connections here with Latour. Both Badiou and Latour envisage love as a sublimatory movement that shifts up from a situation of difference to a situation of unicity and universality. Both stipulate that this movement constitutes a claim to ‘truth’ (‘truth procedure’ in the case of Badiou; ‘regime of truth’ in the case of Latour). However, two key differences are also apparent—these provide a useful entry point by which to consider Latour’s particular approach.
The first concerns the means by which the love relationship is triggered and maintained. For Badiou, this occurs at (what he calls) ‘points’. A point is a particular spatio-temporal moment around which the truth procedure establishes itself and from which it is renewed. The example Badiou offers is that of the birth of a child, which represents a ‘point’ around which the couple (ideally) re-declare their commitment to the original event of their love. For Latour, however, amatory speech shifts up to a regime of truth in a quite different way: for him, a love relationship is not maintained by means of punctuated re-declarations, but rather by means of the creative taking-up of an original event by means of (what he will call) ‘reprise’ (more posts on this most crucial of concepts to follow).
The second difference is a consequence of the first. For Badiou, love can be shifted up to become a truth-procedure. Religion, by contrast, cannot. This is because religion, notwithstanding its rich (Augustinian) appropriation of the lexicon of love vis-à-vis the believer’s participation in divine being, ends up skewing and distorting love as a truth-procedure when it directs it towards the ‘Great Other of transcendence’. Ultimately, for Badiou, religion does not comprehend and cannot handle love because it will inevitably seek to leverage its intensity towards a non-pluralistic end, directing it ‘towards faith and the Church and encouraging this subjective state to accept the sovereignty of God’ (Badiou, In Praise of Love, 2012 , p.66). Badiou calibrates religion instead as a ‘general’ or ‘generic’ conception of truth. Here again is a crucial difference with Latour, for whom amatory speech and religion have a much more organic connection: for him, the empirical situation of amatory speech, when shifted up, provides a very precise calibration of the regime of truth given by [REL]. For Badiou, religion tends towards hegemony: he is wary of it acceding as an overarching and englobing meta-mode. By contrast, for Latour, religion can be justified as a mode of existence with a veridiction that is universal, and yet idiosyncratic to itself.
 For a survey of this particularly French tradition cf. Lancelin, Aude, and Lemonnier, Marie, (2008), Les philosophes et l’amour: aimer de Socrate à Simone de Beauvoir (Paris: Plon); for a sample of such works cf. Breton, André (1937); Barthes, Roland (1977); Nancy, Jean-Luc (2010).
 It should be noted that Badiou’s description is also in critical dialogue with Lacan’s theorization (Seminar XX: On Feminine Sexuality) of jouissance as lust for some part or trait of the other in order to possess it, thus determined by the phallic function, in relation to which there can only be ‘supplementary desire’ on the part of the woman. In fact, Badiou’s commitment to a rigidly ‘empirical’ definition of the phenomenon is markedly less than that of Latour.