On the Epistemology of the Inexact Sciences

72 Pages·2005·2.94 MB·English

ON THE EPISTEMOLOGY
OF THE INEKACT SCIENCES

Olaf Helmer
Nicholas Reacher

Ras3

October 23, 1958

7 RAND cnprcie

sumaRy

Thi 4@ an outline of a new epistemological approsch
to the inexact sciences, which include applied phystee!
sciences such as engineering or medicine as well #6 most of
the social seieces. The purpose of ali sciences 18 to ex
plain past events and to predict future events, and to de 0
tn an objective manner. While in the exect sclences explana—
tion and prediction have the same logical structure, this 18
not so in the inexact solences. This opens the door to the
development of spectfteally predictive inatrumentalities in
these f1elds, and thus ta various methodological innovations.

among these are the ayes:

metic employment of expert judgment
and the use of paculc-experimentation, involving simulation

processes and, in particul

Z, operational gaming.

08

ON THE RPYSTRMOLOGY OF THE INBXACT SCIENCRS

THE MYTHOLOGY OF RKACTNRSS

It 42 @ fiction of 1ong standing that there are two classes
of sciences, the exact and the inexact, and that the social
aciances by and large are members of the second clase—unless
and until, like expertmentel peyehology or some parts of eco—
nomics, they meture to the point where admission te the first
class may be granted.

This widely prevalent attitude seems to ue fundamentally
mistaken; for it finds a difference in principle where there
ip only one of degree, and it imputes to the so-called exact
sefences a procadural rigor which te rarely present in fact.
For the sake of & fuller discussion of these pointe, let us
clarify at the very outeet the terme “science”, “exact science”,
and "inexact science", as they ere intended here.

For an enterprise to be characterized az

entific it

must have as ite purpose the explanation and pradiction of
phenomena within ite subject-aatter domain and it must provide
auch explanatien and prediction in reasoned, and therefore
intersubjective, fashion. We spank of an exact science 1¢

this reasoning proc

4m formalized in the panne that the
terms usad are exactly defined and reasoning takes piace vy
forma] logico-mathamatical darivatian of the hypothesis (the
etatement of the fact to be explained or predicted) from the
evidence (the hody of knowledge accepted by virtue of being

highly confirmed by observation). That an axact science
P1513,
Bon15—58

frequently uses mathematical notation and conceme itnelf
about attributes which lend themselves to exect measurement,

we regard as incidental rather then defining characteriatica.
The sane point applies to the precision, or exactness, of the
Predictions of which the sctence may be eapable, While preciee
pregictions are indeed to be preferred to vague ones, a dis—
sipline which provides predictions of a leas preciee character,
but makeo thew correctly and tn a aystematic and ressoned way,
must be classified as a ectence,

In an inexect setance, conversely, reasoning {e informal;
in particular, soue of the terminology may, without ectualiy
impeding communication, exhibit some inherent vaguenesm, and
reasoning may at least in part rely on reference to intuttively
perceived facts or implications. Again, an inexact science
rarely uses mathematical notation or employs attributes capable
of exact measurement, and a @ rule does not make ite predio—
‘tions with great prectaton and exactitude,

Using the ters as elucidated here—and we be‘ieve that
this corresponds closely to accepted ussge—purely deeeriptive
surveys or summaries, euch as the part of history that 15 mere
chsonology or, ny, purely deacriptive botany or geozraphy,

are not called gefence

Eistory proper, on the other hand,
which seeks to explain historicel transactions and to establish
historical Judgeents having sowe degree of generality, 1s 8
sciences it ts in fact largely colncident with political science,

except that ita practitioners focus their interest on the past
while the political sefentiste! me4n concern 18 the present
and the future,
de for exactness, this qualification, far from being

attributable to all of the so-called natural sciences, applies
only to @ small section of them, in particular to certain sub
fields of physics, in soe of which exactness hay even peen
put to the ultimate test of fomal axiometization. In otner
branches of physics, such as parte of aeredynamies and of tne

physics of extreme temperatures, exact procednr

are stili
Antermingled with unformalized expertise, Indeed the latter
Decomes more dominant ap we move away from the precise ant
usually highly ebstract core of an exact discipline and towards
Ate applications to the complexities of the real werld. Both
architecture and medicine are cases in point. Aside from the
respective activities of building structures and healing people,
poth have a theoretical content,—that ts, they are explanatory
and predictive ("this bridge will not collapse, or has not

epllapsed, because, “ghia patient will exhibit, or has

exhibited, such and such symptoms because..."). They must

therefore properly be called sciences, but they are largely

inexact wince they rely heavily on informal reasoning processes.
If in addition to these examples we remember the esventially

in-between status of euch fields a6 economics and prycholegy,

both of which show abundant evidence of exact derivations a8

well as reliance on intuitive Judgaent (exhibiting intermittent

surable attributes and

use of mathematical symbolinm and of m
PIsL>
ig-is su
a

an occasional sbility te predict with precision) it should be
obvigus that there 1s at present no clear-cut dichotomy vetween
exact and inexact eciences, and, in particular, that inexactness

ie not a prerogative of the sociel seienc

However, leaving aside their present comparative status,
At still mignt be possible to hold the view that there exists
an epistemological difference in principle between the social
eotencea on the one hand and the naturel or physical sciences
on the other, im the sense that the latter, though not neces—
sarily quite exact as yet, will gradually achieve ultimate
exactness, while the former, due to the intangible nature of
their subject-matter and the tmperfection in principle of their
observational data, must of necessity renain inexact. Such o
view would he besed upon false premises, vig., a wholly mic—
guided application of the exactness ve. inexactnese distinc
tion. Indeed, the artificial discrimination between the
physical sciences with their (at least 1n principle} precise
terms, exact derivations and reliable predictions ea opposed
to the vague terme, tntuttive insighte and virtual unpre—
dictability in the social nefences has retarded the develop—
ment of the latter imensurably.

The weagon for thie defestiat point of view regarding the
social sciences may be traceable to a basic misunderstanding
of the nature of scientific endeaver. What matters is not
whether or to what extent inexactitudes in procedures and

predtetive capability ean eventually be removed (with regard