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ON SENSE AND THE SENSIBLE
by Aristotle
translated by J。 I。 Beare
1
HAVING now definitely considered the soul； by itself； and its
several faculties； we must next make a survey of animals and all
living things； in order to ascertain what functions are peculiar；
and what functions are common； to them。 What has been already
determined respecting the soul ＇sc。 by itself＇ must be assumed
throughout。 The remaining parts ＇sc。 the attributes of soul and
body conjointly＇ of our subject must be now dealt with； and we may
begin with those that come first。
The most important attributes of animals； whether common to all or
peculiar to some； are； manifestly； attributes of soul and body in
conjunction； e。g。 sensation； memory； passion； appetite and desire in
general； and； in addition pleasure and pain。 For these may； in fact；
be said to belong to all animals。 But there are； besides these；
certain other attributes； of which some are common to all living
things； while others are peculiar to certain species of animals。 The
most important of these may be summed up in four pairs； viz。 waking
and sleeping； youth and old age； inhalation and exhalation； life and
death。 We must endeavour to arrive at a scientific conception of
these； determining their respective natures； and the causes of their
occurrence。
But it behoves the Physical Philosopher to obtain also a clear
view of the first principles of health and disease； inasmuch as
neither health nor disease can exist in lifeless things。 Indeed we may
say of most physical inquirers； and of those physicians who study
their art philosophically； that while the former complete their
works with a disquisition on medicine； the latter usually base their
medical theories on principles derived from Physics。
That all the attributes above enumerated belong to soul and body
in conjunction； is obvious； for they all either imply sensation as a
concomitant； or have it as their medium。 Some are either affections or
states of sensation； others； means of defending and safe…guarding
it； while others； again； involve its destruction or negation。 Now it
is clear； alike by reasoning and observation； that sensation is
generated in the soul through the medium of the body。
We have already； in our treatise On the Soul； explained the nature
of sensation and the act of perceiving by sense； and the reason why
this affection belongs to animals。 Sensation must； indeed； be
attributed to all animals as such； for by its presence or absence we
distinguish essentially between what is and what is not an animal。
But coming now to the special senses severally； we may say that
touch and taste necessarily appertain to all animals； touch； for the
reason given in On the Soul； and taste； because of nutrition。 It is by
taste that one distinguishes in food the pleasant from the unpleasant；
so as to flee from the latter and pursue the former： and savour in
general is an affection of nutrient matter。
The senses which operate through external media； viz。 smelling；
hearing； seeing； are found in all animals which possess the faculty of
locomotion。 To all that possess them they are a means of preservation；
their final cause being that such creatures may； guided by
antecedent perception； both pursue their food； and shun things that
are bad or destructive。 But in animals which have also intelligence
they serve for the attainment of a higher perfection。 They bring in
tidings of many distinctive qualities of things； from which the
knowledge of truth； speculative and practical； is generated in the
soul。
Of the two last mentioned； seeing； regarded as a supply for the
primary wants of life； and in its direct effects； is the superior
sense； but for developing intelligence； and in its indirect
consequences； hearing takes the precedence。 The faculty of seeing；
thanks to the fact that all bodies are coloured； brings tidings of
multitudes of distinctive qualities of all sorts； whence it is through
this sense especially that we perceive the common sensibles； viz。
figure； magnitude； motion； number： while hearing announces only the
distinctive qualities of sound； and； to some few animals； those also
of voice。 indirectly； however； it is hearing that contributes most
to the growth of intelligence。 For rational discourse is a cause of
instruction in virtue of its being audible； which it is； not directly；
but indirectly； since it is composed of words； and each word is a
thought…symbol。 Accordingly； of persons destitute from birth of either
sense； the blind are more intelligent than the deaf and dumb。
2
Of the distinctive potency of each of the faculties of sense
enough has been said already。
But as to the nature of the sensory organs； or parts of the body
in which each of the senses is naturally implanted； inquirers now
usually take as their guide the fundamental elements of bodies。 Not；
however； finding it easy to coordinate five senses with four elements；
they are at a loss respecting the fifth sense。 But they hold the organ
of sight to consist of fire； being prompted to this view by a
certain sensory affection of whose true cause they are ignorant。
This is that； when the eye is pressed or moved； fire appears to
flash from it。 This naturally takes place in darkness； or when the
eyelids are closed； for then； too； darkness is produced。
This theory； however； solves one question only to raise another；
for； unless on the hypothesis that a person who is in his full
senses can see an object of vision without being aware of it； the
eye must on this theory see itself。 But then why does the above
affection not occur also when the eye is at rest？ The true explanation
of this affection； which will contain the answer to our question；
and account for the current notion that the eye consists of fire； must
be determined in the following way： Things which are smooth have the
natural property of shining in darkness； without； however； producing
light。 Now； the part of the eye called 'the black'； i。e。 its central
part； is manifestly smooth。 The phenomenon of the flash occurs only
when the eye is moved； because only then could it possibly occur
that the same one object should become as it were two。 The rapidity of
the movement has the effect of making that which sees and that which
is seen seem different from one another。 Hence the phenomenon does not
occur unless the motion is rapid and takes place in darkness。 For it
is in the dark that that which is smooth； e。g。 the heads of certain
fishes； and the sepia of the cuttle…fish； naturally shines； and；
when the movement of the eye is slow； it is impossible that that which
sees and that which is seen should appear to be simultaneously two and
one。 But； in fact； the eye sees itself in the above phenomenon
merely as it does so in ordinary optical reflexion。
If the visual organ proper really were fire； which is the doctrine
of Empedocles； a doctrine taught also in the Timaeus； and if vision
were the result of light issuing from the eye as from a lantern； why
should the eye not have had the power of seeing even in the dark？ It
is totally idle to say； as the Timaeus does； that the visual ray
coming forth in the darkness is quenched。 What is the meaning of
this 'quenching' of light？ That which； like a fire of coals or an
ordinary flame； is hot and dry is； indeed； quenched by the moist or
cold； but heat and dryness are evidently not attributes of light。 Or
if they are attributes of it； but belong to it in a degree so slight
as to be imperceptible to us； we should have expected that in the
daytime the light of the sun should be quenched when rain falls； and
that darkness should prevail in frosty weather。 Flame； for example；
and ignited bodies are subject to such extinction； but experience
shows that nothing of this sort happens to the sunlight。
Empedocles at times seems to hold that vision is to be explained
as above stated by light issuing forth from the eye； e。g。 in the
following passage：…
As when one who purposes going abroad prepares a lantern；
A gleam of fire blazing through the stormy night；
Adjusting thereto； to screen it from all sorts of winds；
transparent sides；
Which scatter the breath of the winds as they blow；
While； out through them leaping； the fire；
i。e。 all the more subtile part of this；
Shines along his threshold old incessant beams：
So ＇Divine love＇ embedded the round