The etymology of virtual highlights surprising facets of this concept evolving throughout time.
First there is the Latin virtus which means virtue: "excellence, potency, and efficacy". It concerns the quality of men, virtues of energy, courage, and self-control. “Vir” means man. (The virtual is the reality of the man and not opposed to reality). Later in the XII century, the meaning of virtus changes, it becomes the essence of things, that is to say the principle that is the cause of the effects: like the vertues of plants. In 1503, virtualis appears and means “puissance”, potency or potential: for example, there is a virtual tree in a seed.
We don’t oppose the virtual to reality because virtuality is a reality; we oppose the virtual to the actual. This tree is virtual but not actual, it means it is not actually in the present. However its virtuality is real. In “Difference and repetition” Deleuze calls these realities of things not actualised “intensities” or “pure becomings”. We can’t identify properly these pure becomings, comparing them with other actualisations but according to Deleuze, they have importance for each individual (jealousy is an intensity of love) even if it is not experimented. These intensities influence our acts and our characteristics.

The crucial question is what is a virtual image? I need to find a suitable definition of the virtual in relation to the real. What is a virtual image and what is an image.

Gilles Deleuze is a French philosopher (born in 1925) who wrote many books on literature, cinema and painting. He is considered as a difficult philosopher because of the intensity of his writings. However Gilles Deleuze is a great storyteller and a creator; the most important is to let him guide us in the labyrinths of his thoughts, understand the concepts being less important than feeling things.
In 22 May 1984 he gave an extraordinary lesson on the question of the virtual image in cinema. Deleuze was influenced greatly by