I feel grateful to both Pereira and Garcìa for helping to clarify my thinking about some things that have puzzled me for several years now. In 2004, reading Daniel Colson’s Petit lexique philosophique de l’anarchisme de Proudhon à Deleuze for the first time, I was greatly excited to find exactly what Pereira describes: a rereading of the so-called "classical" anarchists (and the broader history of the anarchist movement) that went "beyond certain limits of the duality between modernity and postmodernity." At the same time, I felt reluctant to embrace what seemed to be an uncomfortable emphasis on "ontology" as the source for the anarchist ethos. I preferred to argue that the most important distinction of anarchist thought (particularly in contrast with Marxisms of all kinds) was that it began not with any speculative thesis about the nature of reality (e.g., are ideas more real than matter, or the other way around?) or history (e.g., is the driving force of history class conflict, or sex, or language, or God, or what have you?) or the human essence (e.g., are people inherently altruistic, or selfish, or aggressive, or imitative, etc.?), but from an _ethical_ standpoint – a rejection of domination and hierarchy, a desire for freedom and equality. As David Graeber puts it, anarchism is fundamentally a discourse centered on the ethics of practice. I had always liked very much Malatesta’s agnostic stance, his pragmatist dismissal of "philosophical" questions: if the philosophical fatalist and the philosophical voluntarist both act as if they had some agency, however conditioned by situations that are presently outside of their control, then for the purposes of collective action, their philosophical differences do not make a difference. So when Pereira, while sympathetic in some respects to Garcìa’s (and Colson’s) project, raises similarly pragmatist concerns about the ontological commitments that Garcìa (and Colson) seem to be asking us to take on, I felt myself in agreement.
At the same time, I have been very suspicious of most varieties of pragmatism for a long time — indeed, for some of the same reasons. That is, the pragmatist reduction of the concept of "truth" to the criterion of usefulness seems to me almost always not only to preclude acknowledgement of a reality that, for better and for worse, is always more and other than what we can "use" (the properties of the planet’s ecology that render certain gases a cause of global warming are not convenient to me, for instance; I would be more comfortable if slavery had never happened and racism didn’t exist; etc.) but also to render other people into objects-for-my-use, pretty much dispensing with ethical commitments right along with the ontological kind. I never wanted to go that far, and I felt that one of the merits of the anarchist tradition was to preserve a degree of realism along with its strong ethical impetus. I felt that anarchism, rather than constituting a kind of political pragmatism, had more of an affinity with Emmanuel Levinas’s insistence that ethics, not ontology, deserved the status of "first philosophy"; that the place to begin thinking was not from an abstract idea but from the concrete experience of encountering something outside myself that cannot ever really be reduced to my concept of it, my uses for it, my desires concerning it – the encounter with the "other" (both other persons and the world itself); that this humbling experience is the beginning of ethics, of respect for the other.
It is Garcìa’s response – interestingly, at a moment when he both resists and finds a point of rapprochement with Pereira’s critique – that helps to clarify for me how I might handle this tension between the ethical and the ontological, between practice and philosophy:

"Anarchism is not theoretically deduced from ontology. Rather, it is our approach to the political act that impels us to flush out the ontological effects of anarchism. We have constructed an ontological discourse from the affirmations, often practical, of anarchism. In this sense, we agree to some extent with I. Pereira to speak of an ’ontology’ of anarchism only in terms of a ’consequence.’ However, we refuse to consider that ’ontology’ as dependent upon a philosophy of anarchism among a plurality of others. We reject this perspective inasmuch as to speak of an anarchist philosophy/philosophies has no sense for us. Anarchism has a multitude of declensions, but these are not philosophical doctrines to which we refer before acting, but politics in acts. They possess their own logic, beyond philosophy and its history, without for that reason ceasing to be thought. To that extent, our philosophical expression encounters no problem in speaking of an ’ontology’ of anarchism."

Here, precisely through their disagreement, both Pereira and Garcìa begin to show me how it is that anarchism produces a kind of pragmatist thought which is at the same time an ethics.
Continued:
PEREIRA, Irène. “On Vivien Garcia’s L’Anarchisme aujourd’hui.”