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: