Very interesting discussion over Deleuze’s views on the relation between philosophical concepts and scientific categories at Footnotes to Plato. I agree with Matt that Deleuze was trying to provide a metaphysics for science and so was criticising the representationalism and the scientism that is not necessarily limited to the “philosophical” talk about science and to their own understanding of their categories and theories (and of their scope), It even has an effect on the content and methods of science, as the opposition between nomad science and state science confirms.
An amusing anecdote comes to mind, dating from 1982, when I attended Deleuze’s seminar on the cinema on Tuesdays, and on Saturdays went to Serres’ class on multiplicities (which gave rise to the books ROME and GENÈSE). On Saturday I would hear an interpretation of the dispute between Bergson and Einstein favorable to Einstein’s position from the point of view of a theory of time (this in Serres class on multiplicities), on Tuesday I would hear a discordant interpretation justifying Bergson’s position (in Deleuze’s class on time and cinema) in the name of the theory of…multiplicities. This difference of interpretation and of evaluation was already amply treated in the previous published work of the two philosophers, without any explicit attempt by one to respond to the arguments of the other. Serres claimed that Bergson was just wrong, siding with a scientistic interpretation in this case (against the tenor of his own work). Deleuze argued that Bergson was misunderstood in the context of the scientism prevailing at the time of the publication of Bergson’s book DURATION AND SIMULTANEITY. According to Deleuze, Bergson was trying to produce the metaphysics appropriate to the revolutions in physical science.
So I can understand Joe Hughes when he claims to have hidden behind the protective covering of an ambiguous word “metaphor”, that he really intended in a non-dualistic etymological sense of “meta-porting”, in order to defuse useless disputes with the ambient scientism of the late 90s. He raises a very interesting question: given the radical difference between scientific categories and philosophical concepts that the naive naturalist simply (and unkowingly) identifies, which for Deleuze and Guattari is a form of reductionism (cf. in WHAT IS PHILOSOPHY? their insistence on “the irreducibility of concepts to functions”) how in the name of transversality are we going to “blend” them? In avoiding reductionism we seem condemned to maintaining not just their irreducibility but, less comfortably, their separation.
It can be argued that this transversal blending can be seen in the work of Ernst Mach, and is explicitly theorised by him. It is also, according to Paul Feyerabend, at work in the theoretical work of Niels Bohr, and also that of Wolfgang Pauli. An interesting contemporary example is that of the economist Frédéric Lordon who argues for the importation (meta-porting) of Spinozist concepts into economic theory. He explicitly cites WHAT IS PHILOSOPHY and its opposition between philosophy (concepts) and science (extensive functions). He argues that economics can achieve the dignity of a science without conforming to the mathematical model by just such a “blending”:
“to increase in intellectual rigour, and perhaps even in objectivity, against Deleuze’s antinomy, science, and in this case social science, must import concepts”. See video in French, approximately 6min30s to 7min:


“Bryant is thrashing within the grips of the ascetic will, as Nietzsche described it” (see comments section here)
I think Jason was making a valid point here, neither dogmatic nor servile nor even lacking in civility. We should distinguish being critical from being uncivil. Jason was using a sort of imagistic conceptual shorthand to situate and qualify a certain problematic. In Continental circles this is done all the time, and you can’t understand a single word of such thinkers if you don’t understand this dance between concept and image. This allows one to say much in a few words.
In the case of Jason’s statement, he manages to say concisely what I tried to express a little long-windedly in response to Levi’s recent pronouncements (http://terenceblake.wordpress.com/2013/05/17/dark-subjectivity-and-an-apodictic-hermeneutics-of-science-on-naturalism-as-nostalgic-pathos/). I think the refence to the ascetic will captures quite nicely the point that Bryant enounces a seemingly objective set of conclusions from science (“the only legitimate conclusions that can be drawn from the state of knowledge today”) but is in fact expressing a very subjective vision of the world and of science.
This pulsation between image and concept is not just decorative but I think it has a quite important function – that of permitting communication across incommensurable paradigms. An analytic approach often insists on commensurability, and feels that remarks coming from a radically different frame of reference are somehow uncivil, aggressive, or even violent and also ridiculous or nonsensical. The Continental approach (but I would argue that this is the case for the pragmatists as well) just does not see such closure of and incommunicability between theories that are semantically very different, precisely because they see another pragmatic dimension that makes communication both possible and potentially fruitful (dare I say enjoyable?).
ANTI-OEDIPUS makes very effective use of this imagistic-conceptual method. It must have seemed very aggressive to closed-minded psychoanalysts, as it treated their profession as a new priesthood submissive to the “ascetic will”. So Jason’s allusion was well-chosen, evoking well-known arguments from Deleuze and Guattari, that they also trace back to Nietzsche. Nietzsche himself uses this same method and was felt to be offensive by the religious-minded of his day and after. I think Jason is quite justified in situating Bryant in this problem-context and even in feeling some amusement at his efforts (thrashing) to escape from its aporia.