so reconciles the rationalist and empiricist strands in Western philosophy and eventu-
ates in demonstrable progress in explaining and predicting the course of events. Lack
of progress means weak theory, bad science, an absence of cumulative findings and
an incentive to devise better (logically sound, empirically testable) theories.^35
Behind Waltz’s affirmative view of science is the Humean presumption that we
can never conclusively know the causes of the world’s many apparent regularities.^36
Where Hume’s constant conjunctions remain constant, we can construe them as
laws. ‘Each descriptive term in a law is directly tied to observational or laboratory
procedures, and laws are established only if they pass observational or experimental
tests’. Concepts such as ‘force, and absolute space and time’ Waltz called ‘theoretical
notions’; his conception of a law in science is another such theoretical notion.^37
Waltz’s conviction that the world consists of observable phenomena and theoretical
notions, neither reducing to the other, makes him a strong positivist.
‘Of purported laws’, Waltz would have us ask, ‘are they true?’^38 But this is not
quite right. We ask instead, can we trust them? Insofar as any given theory seems to
explain the constancy of an empirical generalization, that theory increases our
confidence in the generalization it explains, just as factual constancy increases
confidence in a given theory. Yet this virtuous circle never produces truth beyond
the causal links stipulated to be true by a given theory’s very terms. If a theory is
true, it is true only of, or to, itself, and not true of the world to which it claims
to refer.
Formal causes, institutional effects
As Waltz has said, to form a theory, we must sense a pattern. It is possible that Waltz
has always subscribed to a Platonic doctrine of forms. Behind the many patterns that
our senses make real to us, and their sole cause, is a truly real world, consisting
entirely of perfect forms only dimly available to the senses. Early modern natural
law thinkers advanced a similar metaphysical doctrine. By exercise of reason, we can
find the underlying order of the world in what we see. Even now, quite a few
scientists reflexively hold this view. Constant conjunctions are no accident, laws
capture truths, theories order laws, science finds the larger truth informing laws we
know to be true.
On the evidence presented in the preceding section, I doubt that Waltz is, or
has ever been, a Platonist or, in Kant’s terms, a dogmatic philosopher. Waltz would
seem to be closer to Aristotle than to Plato or the dogmatic rationalists. Aristotle
rejected Plato’s doctrine of forms: ‘things cannot come from the Form in any of the
usual senses of “from”’.^39 Nevertheless, forms matter, but not as matter. Consider
the second of Aristotle’s four senses of the termcause– material, formal, efficient
andfinal. A formal causeis the ‘form [eidos] or pattern [paradeigma], that is, the formula
[logos] of the essence [ti esti, what is, rendered by medieval Platonists as essentia, is-
ness]’.^40
Aristotle used the production of a bronze sphere to illustrate formal causality. We
see spheres in the world consisting of various materials (for example, water droplets,
94 Structure? What structure?