1 The Birth of Science - MSRI

152 6. The Hellenistic Scientific Method
wrote that every sensation is obtained through an active participation of
the intellectual faculties, even if we’re not conscious of it. 17
It is important to notice the distance in meaning between the Greek page 196
word phainomenon, which refers to the interaction between subject and
object constituted by perception, and our derived word phenomenon. In
modern times phenomena have long been considered simply as facts that
take place independently of, and can be known directly by, the observer,
through a mechanism that need not be looked into. Now the point for us
is that Sextus Empiricus identifies for us the only epistemological element
about which there was no doubt at all (even among Skeptics!) in Hellenistic
times. 17a Not long before the passage cited, he gives a more specific
example:
For a Skeptic gives his assent to impressions caused necessarily by
sensation: for example, being hot or cold, he would not say, “I don’t
think I’m hot or cold”. 18
Sextus Empiricus was a physician. It is possible that his example was
not independent of the analogous observation made centuries earlier by
Herophilus and reported by Galen:
So what does [Herophilus] say? “It is by nature impossible to find out
whether there is a cause or not; but I can assess whether I’m cold, or
hot, or satiated with food or drink.” 19
and the bibliography in [CHHP]. A recurring motive in Hellenistic mosaics is a tiling by cubes in
parallel perspective, seen along the direction of the diagonal (so as to form a hexagonal tessellation)
and shaded accordingly. Their corners can be perceived alternately as sticking out or in (see
examples in [Dunbabin], pp. 223–224, 339). Possibly this phainomenon was explained through the
possibility of assenting to different interpretations of the same impression.
17 Plutarch, De solertia animalium, 961A.
17a Here we are interested more in the method actually used by scientists than in the epistemological
musings of Hellenistic philosophers (who, in the surviving fragments, rarely deal with scientific
theories). But it is nonetheless significant that to several Hellenistic philosophical schools, various
aspects and forms of perception lie at the base of knowledge: to the Cyrenaics, feelings (: Eusebius,
Praeparatio evangelica, xiv, 19.1); to the Epicureans, perception (©: Epicurus, Letter to
Herodotus, 49–53); to the Stoics, impression (©: Diogenes Laertius, VII, 50; Sextus Empiricus,
Adversus dogmaticos, I, 250–251). We will discuss later the notion of (also translated as
perception).
18 Sextus Empiricus, Pyrrhoneae hypotyposes, I, vii, 13.
19 “Quid igitur [Herophilus] ait? ‘causa vero, utrum sit vel non, natura quidem non est invenibile,
existimatione autem puto infrigidari, estuari, cibo et potibus repleri’” (Galen, De causis procatarcticis,
XVI, 197–204 = [von Staden: H], text 59a, 7–9). Von Staden interprets it differently, translating
“. . . it is through a supposition that I think I am chilled. . . ”. Galen, who is criticizing Herophilus,
may in fact be using “existimatio” to some such effect. But even not taking into account the preceding
passage by Sextus, it seems to me that the original word translated “existimatio” in the
Latin, referring as it does to the perception of sensations such as cold or satiety and counterposed
with the impossibility of verifying causes, was probably not being used by Herophilus in a limiting
function.
Revision: 1.7 Date: 2002/09/14 23:17:37