"Medieval philosophers were fascinated by mirrors. They inquired in particular into the nature of the images that appear
in them: What is the being, or rather the non-being, of these
images?
[...]
Two characteristics are derived from the insubstantial nature of the image. Since the image is not a substance, it does
not possess any continuous reality and cannot be described as
moving by means of any local movement. Rather, it is generated at every moment according to the movement or the presence of the one who contemplates it: "Just as light is always
created anew according to the presence of the illuminator, so
do we say that the image in the mirror is generated each time
according to the presence of the one who looks."
The being of the image is a continuous generation (semper
nova generatur), a being [essere] of generation and not of substance. Each moment, it is created anew, like the angels who,
according to the Talmud, sing the praises of God and immediately sink into nothingness.
The second characteristic of the image is that it cannot be determined according to the category of quantity; it is not, properly speaking, a form or an image but rather the "aspect of an
image or of a form" (species imaginis et formae). In itself, it cannot be described as long or wide, but instead as "having only
the aspect of length and width." The dimensions of the image
are therefore not measurable quantities but merely aspects or
species, modes of being and "habits" (habitus vel dispositiones).
This characteristic - being able to refer only to a "habit" or an
ethos - is the most interesting signification of the expression
"being in a subject." What is in a subject has the form of a
species, a usage, a gesture. It is never a thing, but always and
only a "kind of thing" [specie di cosa].
The Latin term species, which means "appearance," "aspect," or
"vision," derives from a root signifying "to look, to see:' This root is also found in speculum (mirror), spectrum (image, ghost),
perspicuus (transparent, clearly seen), speciosus (beautiful, giving itself to be seen), specimen (example, sign), and spectaculum
(spectacle). In philosophical terminology, species was used to
translate the Greek eidos (as genus was used to translate genos);
hence the sense the term takes on in natural science (animal or
plant species) and in the language of commerce, where the
term signifies "commodities" (particularly in the sense of
drugs and spices) and, later, money (especes).
[...]
The mirror is the place where we discover that we have an
image and, at the same time, that this image can be separate
from us, that our species or imago does not belong to us. Between
the perception of the image and the recognition of oneself in
it, there is a gap, which the medieval poets called love. In this
sense, Narcissus's mirror is the source of love, the fierce and
shocking realization that the image is and is not our image.
If the gap is eliminated, if one recognizes oneself in the
image but without also being misrecognized and loved in it - if
only for an instant - it means no longer being able to love; it
means believing that we are the masters of our own species and
that we coincide with it. If the interval between perception and recognition is indefinitely prolonged, the image becomes
internalized as a fantasy and love falls into psychology.
In the Middle Ages, species was also called intentio, intention.
The term names the internal tension (intus tensio) of each
being, that which pushes it to become an image, to communicate itself. The species is nothing other than the tension, the
love with which each being desires itself, desires to persevere
in its own being. In the image, being and desire, existence and
conatus* coincide perfectly. To love another being means to
desire its species, that is, to desire the desire with which it
desires to persevere in its being.
[...]
The transformation of the
species into a principle of identity and classification is the original sin of our culture, its most implacable apparatus [disposiuvo]. Something is personalized - is referred to as an identity at the cost of sacrificing its specialness. A being - a face, a gesture, an event - is special when, without resembling any other,
it resembles all the others.
Giorgio Agamben Profanations (2007) p.55-58
* striving - an innate inclination of a thing to continue to exist and enhance itself