Among the various writers who have challenged the ideologies of “objective history” (e.g., Heidegger, MacIntyre, Ricoeur, White, and, most recently, Megill’s Historical Knowledge, Historical Error), it was Deleuze who has most insistently pressed the issue despite rarely explicitly thematizing the problem as being “historical”. We cannot, Deleuze says, speak of “the” history of philosophy but, rather, only of histories of philosophy. (Is this not also a direct consequence of the famous relevant sections of Being and Time?)
When Deleuze’s monographs explicate a history of philosophy, each author is presented as a complex or a composite: it is well-known that Deleuze’s Bergson, Spinoza, and Nietzsche are inseparable, for example; Deleuze is explicit about the “monstrous children” of philosophy in this regard.
We can escalate this procedure in the case of Bergson and Merleau-Ponty by literally intertwining two texts on philosophy and history:
the relation of philosophy to earlier and contemporary philosophies is not … what a certain conception of the history of systems would lead us to assume. [Bergson] Between an “objective history of philosophy” … and a meditation disguised as a dialogue … there must be a middle-ground on which the philosopher we are speaking about and the philosopher who is speaking are present together, although it is not possible even in principle to decide at any given moment just what belongs to each. [Merleau-Ponty] The philosopher does not take pre-existing ideas in order to recast them … The truth is that above the word and above the sentence there is something much more simple … [i.e.,] the meaning [sens], which is less a thing thought than a movement of thought, less a movement than a direction. [Bergson]
In a letter, Bergson would say that an “ism” is not merely the name of the set of principles held by a particular doctrine but rather a “tendency, a direction of thought followed by a philosopher”. Is this not precisely what Deleuze means by presenting a “Bergsonism” under the guise of a “return to Bergson”? This is obviously not a reactionary move; Bergson performatively made the same point when he instructed his executors and wife to destroy many of his writings on his death.
The “history of philosophy”, above all, must resist the temptation to become a museum or a marketplace. The task of history is to attest (this word is important) to the “life” of ideas. History is not this life; nor can history—lest it devolve into the ideologies of “objective history”—orient itself toward the ideas themselves (nor to concepts—Deleuze, again). The only proper history of philosophy is neither philosophical nor historical but, rather, metaphilosophical and, perhaps, metaxiological.