Gilles Deleuze refuses the pure Platonic light of positivity and aids us in confronting the shadow inside the cavern and befriending it. There are a plethora of negative prefixes in Deleuze’s texts (in-, a-, de-, non-, un-), which are the markers of the de-stabilisation of signification and of the emergence of new meanings. Such is the motor of the free play of interpretation.
A Platonic philosopher such as Graham Harman enshrines a real of pure positivity and stasis (as time is unreal for Harman’s philosophy) and condemns interpretation and transformation to the sensual, unreal, realm. Yet for Deleuze the sensual realm is that of intensity and metamorphosis, and its pluralism of interpretation goes with his battle cry:
“Everything must be interpreted in terms of intensity”.
Another Deleuzian negative prefix is “dis-” as in disjunction, dissemblance, and also difference (dif- is a variant of dis-). Any idea of a continuist or “lavalampy” Deleuze is not just mistaken, absurd, laughable, it is strictly illiterate: it cannot read the letter of Deleuze’s text. I think that it is very important to correct the dualist black vs white grid which has been imposed on Deleuze’s work. “Negativity” is not the opposite of positivity, but part of the affirmation of all the intensities between, and including, these extremes.
For a closely related notion the role of darkness and negativity in Deleuze see Andrew Culp’s Dark Deleuze Project.