Paul Keyser
Scholars contemplating the nature of scientific endeavor since ca 1600 AD have often argued that
“experiment” is a distinctive or even definitive feature of “science,” and correlatively that “experiment”
was absent in prior endeavors, which are thus excluded from “science.” However, the claim that
science emerges like a sudden breakthrough assumes either the emergence of new cognitive capacities,
or the new deployment of existing capacities, and neither hypothesis admits a sensible account of how
that could occur (Lloyd 2009, 159–160).
Francis Bacon (1620) clarified how experience is crucial to developing scientific models:
unorganized experience shows a path to organized experiences (i.e., experiments), that then lead to
theories, which in turn motivate further experiments (§1.82, 1.117). Although Bacon himself criticizes
Greek scientists for their lack of experiments (§1.63, 1.73), his definition allows a sliding scale of
increasingly organized experiences, which when sufficiently digested and ordered are experiments (cf.
Frey 2015). Bacon (1620) §2.21–52 even seems to categorize kinds of organized experiences.
Granted that science existed in antiquity, experience was always an element of scientific
thought. So, when does “experience” become “experiment”? Not all at once, but by degrees. I will
argue that experiment-design and theory-creation co-evolve, and that the early stages of this evolution
are visible in the Hippocratic corpus, and in some contemporary documents, notably Herodotus and
Thucydides. Moreover, as argued by Lloyd (1964 / 1991), and von Staden (1975), we should not expect
the deployment of “experiment” (or even experience) to be uniform and systematic.
The role of repeated experience, as encountered, is shown in a passage of Thucydides (3.20.3),
where measurements (of the height of a distant wall) by many people produce a more reliable result.
Likewise, Herodotus often deploys (encountered) experience to reject earlier descriptions of the world,
especially those that posit a circular Ocean-stream around a discoid Earth (4.36.2). The many authors
of the Hippocratic corpus more systematically deploy experience and experiment to promote their
views and confute their opponents. I will examine four sets of texts from that corpus. Breaths proposes
a scientific program for the improvement of surgery, based on experience, apparently primarily
multiple encountered experiences. Nature of the Child describes a carefully-constructed experience
(observing the development of fertilized chicken eggs) held to demonstrate by analogy fetal
development in humans. For Bacon (1623) §4.2, the Epidemics were exemplary of his method: each
section displays features consistent with the “case-study” of Forrester (1996), and the authors organize
their experiences by grouping the cases to demonstrate a model of disease etiology and progression,
and sometimes to record the results of attempts (i.e., experiments) in treatment. Ancient Medicine
claims that proper diet has been developed through extensive experiments, as have many procedures of
medical treatment. The four texts display different degrees and kinds of experiment, from encountered
experience through well-organized systematic experiments, although the works do not constitute a
uniform chronological sequence.