Sensation and Thought
seeming temporal order in the Metaphysics
(Book I, Chapter 2) for the Presocratics by
category (in his account Aristotle leaves out some important philosophers
while including some obscure ones that I do not include here):
that believed in one or more ingenerable and
imperishable substances, whose changing modifications cause generable and
ii. Anaximenes (he doesn’t mention Anaximander here)
that believed that all is one, but appears to sensation to be many
chronological orders in the three categories are independent, and in fact
Aristotle says that the Pythagoreans were “contemporary with these
philosophers and before them.” Since Xenophanes was earlier than
Heraclitus, it appears that the three lists comprise three
Democritus, Socrates, presumably Plato, and Aristotle all made a
distinction between sensation and thought as
knowing faculties. This handout attempts to trace the development and
perpetuation of this distinction.
Parmenides’ poem, sensation and thought respectively reveal distinct
worlds with opposite characteristics:
world of sensation comprises a pluality of
things and is characterized by a variety of cyclical changes that were
the main object of explanation (explanandum,
thing to be explained) of the Ionian philosophers.
world of thought is one and unchanging.
the world of sensation is immediate and evident. Our experience begins there.
the world of sensation is contradictory, and so must yield as regards
truth, to the world of thought.
thus, is introduced into out experience by its critical power, that is,
its ability to detect contradiction in the world of sensation.
character of Being, the world of thought, is a result of applying the
requirements, as Parmenides sees them, of the critical power of
thought, and especially the principle of contradiction as he formulates
it (what is cannot not be).
paradoxes, as befitting something designed to shore up Parmenides’ way of
truth, dwell in the arena of thought. Of the two classes of paradoxes, the
paradoxes of plurality are more important for his immediate successors,
and of motion for Aristotle.
of the paradoxes of plurality: if the many are, they must be large and
small—so large as to be infinite (as a totality), and so small as
to be non-existent.
are many, if and only if, the one (all, whole) can be divided into many.
things are many, then the all has been divided either finitely or infinitely.
finitely, then the many then are also infinite in number, because their
boundaries constitute others, and the boundaries between the boundaries and the
bounded, ad infinitum. Thus they are
both finite and infinite in number.
infinitely, then since they have been infinitely divided, they are so small as
to have vanished entirely, and in the process, the number and sum of their
differences have become infinite. Thus they are as a totality both non-existent
and infinite in extent.
to J. E. Raven’s treatment of Anaxagoras, aspects of the latter’s
cosmology are based on a rejection of a strand of reasoning in Zeno’s
paradoxes of plurality, namely the notion that if things were infinitely
divisible, they would be both infinitely small (and thus non-existent)
and infinitely large as a totality. Anaxagoras accepts the notion that
things can be both reduced and expanded without limit.)
this stage of this handout I am leaving out Empedocles.)
According to J. E. Raven, his philosophy is based on accepting Parmenides’
ban on coming to be and passing away, but rejecting his ban on division.
(Things are infinitely divisible, and pace
Zeno, this results in no impossibility.)
characteristic of things has ever come to be or will ever pass away.
Rather, originally all things were together, that is, each characteristic
was divided so finely as not to be apparent, and all were thoroughly
combination and separation due to the vortex having been started by Mind,
the characters of things have become apparent through like being combined
with like, and unlike being separated from unlike. Yet all things still
have all things within them, but mostly in parts too small to be apparent.
the world as it is now is manifest to sensation, whereas the original
togetherness and the work of the vortex process are inferences of
thought. Why must there have been a togetherness?
Perhaps the original togetherness is just an ideal limit—what really
needs to be explained is the apparent coming to be and passing away of
things with definite characteristics.
Democritus’ atomism, the cosmology of the atoms and the void is likewise
the result of critical reflection on the sense world, although that process
of reflection must be reconstructed (since it is not fully in our texts
process might be somewhat as follows:
qualities (color, sound, etc.) come to be and pass away. But coming to be and
passing away are impossible (because what is cannot not be). Hence, sense
qualities are unreal and in particular relative, that is, they arise in the
interaction of the sensed and our sense organs. (These interactions can come to
be and pass away.)
interaction implies plurality and change, but not true becoming or passing away
(the coming to be and passing away of what is).
there must be indivisibles (atoms) (because otherwise there would be nothing
not susceptible to coming to be and passing away, or perhaps he accepts Zeno’s
argument against infinite divisibility), and there must be a void (because
otherwise the atoms would not be able to move).
do not see the atoms, but only infer them (everything we see is
divisible)—hence they are too small to see.
just as in Parmenides, there are two worlds, one revealed though the senses,
and one through thought.
it would not be an oversimplification to say that sensation reveals the
immediate and apparently clear world, while thought reveals its underlying
nature. Thought as such seems to be characterized by logic, although there
certainly seems to be a logic of sensation of a
As in the Republic, there are
two worlds, the intelligible and the sensible, one apprehended by thought
and the other by sense. The intelligible is the cause of the sensible, and
the sensible can be understood only through the intelligible.
The whole point of this handout is to try to clarify Aristotle’s view of
the distinction between sensation and thought.
is clear from the texts:
possess two kinds of knowing faculties, sensation and thought, the latter being
possessed only by human animals.
is of the individual or particular, thought of the universal.
acquires meaning through a combination of convention (various nations speak
various languages) and a kind of modeling of reality in the soul.
mind possesses the capacity to form universals from complex sensations in the
or belief and knowledge are distinct, and one cannot opine and know the same
know P is to possess a proof of P.
is unclear from the texts but important:
this is unclear and gives rise to difficulties, the assertions just emunerated seem to imply that “meanings” are of two kinds,
complex sensations as recorded in memory, and universals. So the name “Socrates”
acquires meaning through sensation, while the name (noun) “human being”
acquires meaning through a two-step process involving sensation and thought.
Thus it seems that a proposition as it exists in the mind can be composed
either of complex sensations or of thoughts (universals)—examples: “Socrates
is here” vs. “All humans are mortal.”
seems unsatisfactory as regards logical relations between universal and