The sentient will perceive all features of the object only by discerning all the
features of all its parts. That being so, the contemplation by which the true forms
of visible objects are perceived is achieved both by the eye itself and by the faculty of
judgment. Perception of the true forms of visible objects can therefore take place
only by means of contemplation. And the contemplation by means of which the
object’s form is ascertained can be affected only by the eye’s movement.^71
This, of course, takes time. He thus distinguishes between the immediate
apprehension of visual information, which he refers to as‘glancing’sight,
and the processes of judgment that amount to‘contemplative’sight.
Sight...perceives only the forms of visible objects, and each of these forms is
composed of a number of particular properties and, consequently, sight perceives
in each of the forms of visible objects a multitude of particular properties [which
are then distinguished] in the imagination and the faculty of judgement.^72
The form of each part will not be ascertained, nor will all features in the object be
manifest until after the eye has moved over all parts, and after the axis (or a line
close to it) has passed over each of them. Moreover, it is in the nature of sight to
engage in this action of contemplation, thus passing the ray’s axis over all parts of
the object, so that when the faculty of judgement decides to contemplate an object,
the ray’s axis will move over all parts of it.^73
For ibn al-Haytham, this glancing sight is incomplete before being pro-
cessed through contemplation. Thus sensory, verifiable, experimental evi-
dence alone does not add up to knowledge, which can only be attained
through the process of judgment. All perception is instantaneous, gaining
signification as it becomes composite through the internalization of judg-
ment, and only becomes meaningful through the reflection of memory.
Both thinkers posit sight less as the apperception of an external world
than as its contemplative internalization. This idea reverberates with
Plotinus’suggestion that“Creation is not so much a making (poiesis)asa
contemplation (theoria): the activity of contemplation, says Plotinus,pro-
ducesthe object contemplated.”^74 Nader El-Bizri similarly glosses ibn
Haytham, saying:“It is by way of imagination that theeideticessence of a
thing, which is represented by its (sura al-kulliya), becomes accessible, and
designates the wholeness of the appearing structural properties of that
individual entity and its classing among analogous species.”^75 Likewise,
Plotinus explains that human sensation requires powers that split up the(^71) Sabra, 1989 : 210. (^72) Sabra, 1989 : 207. (^73) Sabra, 1989 : 210. (^74) McEvilley, 1980 : 182.
(^75) El-Bizri does not translatesura al-kulliya; I propose‘composite image,’referring to the idea that
emerges of the many points on the object that come together via judgment in the imagination as
the image of the thing. El-Bizri, 2005 : 193.
126 Seeing with the Heart