Virtual (philosophy)

Virtuality is a concept in philosophy, particularly that of French thinker Gilles Deleuze.

Deleuze used the term virtual to refer to an aspect of reality that is ideal, but nonetheless real. An example of this is the meaning, or sense, of a proposition that is not a material aspect of that proposition (whether written or spoken) but is nonetheless an attribute of that proposition. Both Henri Bergson, who strongly influenced Deleuze, and Deleuze himself build their conception of the virtual in reference to a quotation in which writer Marcel Proust defines a virtuality, memory as "real but not actual, ideal but not abstract". A dictionary definition written by Charles Sanders Peirce supports this understanding of the virtual as something that is "as if" it were real, and the everyday use of the term to indicate what is "virtually" so, but not so in fact.

Deleuze's concept of the virtual has two aspects: first, the virtual is a kind of surface effect produced by actual causal interactions at the material level. When one uses a computer, the monitor displays an image that depends on physical interactions happening at the level of hardware. The window is nowhere in actuality, but is nonetheless real and can be interacted with. This example actually leads to the second aspect of the virtual that Deleuze insists upon: its generative nature. This virtual is a kind of potentiality that becomes fulfilled in the actual. It is still not material, but it is real.

Deleuze argues that Henri Bergson developed "the notion of the virtual to its highest degree" and that he based his entire philosophy on it. In Bergsonism, Deleuze writes that "virtual" is not opposed to "real" but opposed to "actual", whereas "real" is opposed to "possible". This definition, which is almost indistinguishable from potential, originates in medieval Scholastics and the pseudo-Latin "virtualis". Deleuze identifies the virtual, considered as a continuous multiplicity, with Bergson's "duration": "it is the virtual insofar as it is actualized, in the course of being actualized, it is inseparable from the movement of its actualization."

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