The most eminent philosophers of antiquity, Democritus, Socrates,
Aristippus the chief of the Cyrenaïc sect, Plato, Epicurus, and
Lucretius, affirmed, that cold and heat, odours and colours, were no
other than sensations excited in our minds, by the different operations
of the bodies surrounding us, and acting on our senses; even Aristotle
himself was of opinion, that “sensible qualities exist in the mind.” Yet
when Descartes, and after him Mallebranche, taught the very same truths,
they were ascribed to these moderns, owing to the outcry they made, as
if the opposite error, which they attacked in the schoolmen, had been
that of all ages; and nobody deigned to search whether, in reality, it
was so or not. Were we to bring into review all that the ancients have
taught on this subject, we should be surprised at the clearness with
which they have explained themselves, and at a loss to account how
opinions came to be taken for new, which had been illustrated in their
writings with such force and precision.
Democritus was the first who disarrayed body of its sensible qualities.
He affirmed, that “the first elements of things having in them naturally
neither whiteness nor blackness, sweetness nor bitterness, heat nor
cold, nor any other quality, it thence follows, that colour, for
example, exists only in our imagination or perception of it; as also,
that bitterness and sweetness, which exist only in being perceived, are
the consequences of the different manner in which we ourselves are
affected by the bodies surrounding us, there being nothing in its own
nature yellow or white, or red, sweet or bitter.” He indicates what kind
of atoms produce such and such sensations: round atoms, for example, the
taste of sweetness; pointed and crooked, that of tartness; bodies
composed of angular and coarse parts, introducing themselves with
difficulty into the pores, cause the disagreeable sensations of
bitterness and acidity, &c. The Newtonians imitate this reasoning
everywhere, in explaining the different natures of bodies.
Sextus Empiricus, explaining the doctrine of Democritus, says, “that
sensible qualities, according to that philosopher, have nothing of
reality but in the opinion of those who are differently affected by
them, according to the different dispositions of their organs; and that
from this difference of disposition arise the perceptions of sweet and
bitter, heat and cold; and also, that we do not deceive ourselves in
affirming that we feel such impressions, but in concluding that exterior
objects must have in them something analogous to our feelings.”
Protagoras, the disciple of Democritus, carried farther than ever
Democritus did the consequences of his system; for admitting with his
master the perpetual mutability of matter which occasioned a constant
change in things, he thence concluded, that whatever we see, apprehend,
or touch, is just as they appear; and that the only true rule or
criterion of things, was in the perception men had of them. From
Protagoras, bishop Berkeley seems to have derived his idea, “that there
is nothing in external objects but what the sensible qualities existing
in our minds induce us to imagine, and of course that they have no other
manner of existence; there being no other substratum for them, than the
minds by which they are perceived, not as modes or qualities belonging
to themselves, but as objects of perception to whatever is percipient.”
We should think we were listening to the two modern philosophers,
Descartes and Mallebranche, when we hear Aristippus, the disciple of
Socrates, exhorting men “to be upon their guard with respect to the
reports of sense, because it does not always yield just information; for
we do not perceive exterior objects as they are in themselves, but only
as they affect us. We know not of what colour or smell they may be,
these being only affections in ourselves. It is not the objects
themselves that we are enabled to comprehend, but are confined to judge
of them only by the impressions they make upon us; and the wrong
judgments we form of them in this respect is the cause of all our
errors. Hence, when we perceive a tower which appears round, or an oar
which seems crooked in the water, we may say that our senses intimate so
and so, but ought not to affirm that the distant tower is really round,
or the oar in the water crooked: it is enough, in such a case, to say
with Aristippus and the Cyrenaïc sect, that we receive the impression of
roundness from the tower, and of crookedness from the oar; but it is
neither necessary nor properly in our power to affirm, that the tower is
really round, or the oar broken; for a square tower may appear round at
a distance, and a straight stick always seems crooked in the
water.”[312]
Everybody talks of whiteness and sweetness, but they have no common
faculty to which they can with certainty refer impressions of this kind.
Every one judges by his own apprehensions, and nobody can affirm that
the sensation which he feels when he sees a white object, is the same
with what his neighbour experiences in regard to the same object. He who
has large eyes will see objects in a different magnitude from him whose
eyes are little, and he who hath blue eyes, discern them under different
colours from him who hath grey; whence it comes, that we give common
names to things, of which, however, we judge very variously.
Epicurus, admitting the principles of Democritus, thence deduces “that
colour, cold, heat, and other sensible qualities are not inherent in the
atoms, but the result of their assemblage; and that the difference
between them flows from the diversity of their size, figure, and
arrangement; insomuch, that any number of atoms in one disposition
creates one sort of sensation; and in another, another: but their own
primary nature remains always the same.”
The moderns have treated this matter with much penetration and sagacity,
yet they have scarcely advanced any thing but what had been said before
by the ancient philosophers just quoted, and by others who might be
cited to the same effect.
[312] Peter Huet, the celebrated bishop of Avranches, in his “Essay on
the Weakness of the Human Understanding,” argues to the same effect,
and almost in the same words. ED.
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_For the Table Book._