Opinion, against philosophy.
The three disciplines advance by crises or shocks in different ways, and in each case it is their sucession that makes it possible to speak of "progress." It as if the struggle against chaos does not take place without an affinity with the enemy, because another struggle develops and takes on more importance - the struggle against opinion, which claims to protect us from chaos itself. WiP p.203
Opinion: a negative term used by Deleuze and Guattari in What Is Philosophy?
Opinion does refer to a specific machinic phylum, but one that invades and parasitises those of art, science and philosophy. The three disciplines, each with their own machinic phyla (creative engine), pass through chaos (change) in their own ways. This relation to chaos defines each discipline. But opinion offers a quick and easy solution to each, a stereotypical creativity – perhaps implying a departure from the appropriate form of creativity, and more contentiously, freedom of expression (see previous entry).
Perhaps it does this by making too immediate and ill-considered a transversal move between phyla: for example, conceptual art. In philosophy it appears as transcendence. In art as the figurative or symbolic. Sophistry.
This also relates to the debate between Klee and Kandinsky concerning the relationship between forms in painting and music.
But opinion is a machinic phylum in itself – is it a phylum of the viral? Of the retrovirus? – as I said in Deleuze and Philosophy.