Discourses, Foucault and Genealogies

Recently, I got into a disagreement with a colleague about the type of work Foucault does as proper philosophy. The typical strand of argument I got is no different than other analytic philosophers skeptical of CP. This feels heuristic more than precise, but here goes.

P1: If discourses are meaningful, then the discourses are in some way compatible with the natural sciences
P2: Discourses are meaningful
C: Therefore, discourses are in some way compatible with the the natural sciences.

In order to resist this argument, I reject that the only way discourses are meaningful is in their demonstrated compatibility with the sciences. Take for instance, when I encounter objects in the world, I first encounter them as available to my use, as objects of equipment. I encounter the world first in terms of my practical engagement with the world such that objects are encountered in what we might call the nexus of human purposes. I don't encounter a watch or a chair as objects with a stable electron configuration, as an object described by physics. Instead, I see it as related to my ends or purposes. Moreover, I postulate that I can still have an understanding of the world such that I can have an entire discourse describing my encounter with objects in my experience that pump the intuition that compatibility with the sciences is not the hallmark of a good discourse. It is just one possible formulation.

Likewise, the point I am driving at is simple. There are more than just philosophy qua science approaches in philosophy. In order to see that, consider a more positive argument to establish an example of responsible CP work.

P1: All discourses have norms that establish the standard of truth for that discourse
P2: Science is a discourse
P3: Therefore, science has norms that establish the standard of truth for that discourse.
P4: Normative standards are constituted by their socio-historic and socio-political conditions of the agent's doing science
P5: Nietzschean genealogies qua method provide access to how normative standards are constituted
C: Therefore, any theorist using Nietzschean genealogies as a theoretical device can explain the socio-historic and socio-political conditions of a discourse, including science.

The implication of the conclusion is that Foucault and Deleuze are employing responsible methods for what undergirds one type of human activity, science. This entire line of thinking also takes seriously Nietzsche's claim about history in the "(History Essay)...Uses and Abuses..." in that we are historically finite knowers and that understanding must reflect our position as finite knowers. These discourses are meaningful ways to understand the social conditions of how we do understand the world, and provide ways of encountering past philosophies as uncharitable to our finitude. Instead, classical epistemologies for instance construe our knowing as exemplified by some ideal epistemic agent that if these necessary and sufficient conditions are met, then we can know what it means to know. However, finitude cannot be avoided. Denying our finitude amounts to refusing to see how understanding is shaped by our historical situation. In the same token, Heidegger and Gadamer embrace this same concept, providing us with ways to interrogate the structure of discourses that persist not independent of our history, but shaped by it.

My opponent could refuse P1. He could say that there are discourses independent of norms. Yet, I cannot think of how a counter-factual would go that could deny the fact that discourses are a human activity. Maybe, you could give me one, maybe not.