soap bubbles), just as we see disks (the sun, moon). Any given sphere is made ‘by art
[technê] or by nature [phusis, the whole to which all causes ultimately lead] or by some
capacity [dunamis, developmental potential, where form is an emergent property]’.^41
Forms have many sources in a world already laden with forms. Forms must be realized
materially; they give the formless stuff of the world recognizable properties. Mindless
empiricism and pure materialism are no more plausible than Platonic idealism.
Aristotle’s use of the term poieô(to make or produce) does favour art over nature
in telling us where forms ‘come from’.^42 ‘But that there is a bronze sphere, this we
make. For we make it out of the bronze and the sphere; we bring the form into this
particular matter, and the result is a bronze sphere’.^43 Given this example (Aristotle’s
only one), it would seem that form – in this case a spherical form – is a property
that an artisan gives to a formless medium such as bronze (which is then a material
cause). In such a case, the artisan must have this form in mind, as a goal, and use it
as a model or pattern (thereby serving as the efficientcause).
Aristotle’s conception of formal cause is ambiguous. It does seem to imply the
prior existence of a model (map, formula). If not a Platonic essence, then the model
must ‘come from’ a human mind and be given to the stuff of the world. Produced
as an imaginative act, the model generalizes and idealizes the human experience with
relevant forms. What then does anyone using the model produce? It can only be a
model: a sphere that happens to be made of bronze, or an object unlike any other
that testifies to the imaginative power of the mind responsible for it, or an aeroplane
that, as a working model or prototype, invites the production of any number of
aeroplanes of the same model.
Every model assigns formal properties to its contents. If the model stipulates a
formal causal relation between some set of elements making it up, then thatrelation
is internal to the model. As a theorist, Waltz has formed a model of international
politics in which a formally specified structure functions as a formal cause. That cause
has effects that are no less formal – they are entailed by the model, as a closed system
of relations, and they can only take place within the model.
‘A systems approach is successful only if structural effects are clearly defined and
displayed’.^44 Given Waltz’s Aristotelian model of models, this demanding standard
must be honoured. He issued it in a critique of Morton Kaplan’s several models of
international systems. In turn, Kaplan criticized Waltz for denying that Kaplan’s
models properly specified structural causes.^45 In my opinion, Theory of International
Politicswarrants criticism because it fails to meet Waltz’s own standard for specifying
structural effects.
Two chapter titles reveal as much: ‘Structural causes and economic effects’ and
‘Structural causes and military effects’ (Chapters 7 and 8). Few of these effects are
‘structural’ in the formal sense that Waltz’s model requires. Thus Waltz opened the
second of these chapters with a brief discussion of stability as a structural effect in
balance of power systems. Indeed, states of (in)stability or (dis)equilibrium are
standard concerns in systemic theorizing, and they are typically treated in functional
terms. Passing over these concerns, Waltz’s discussion quickly turned to the institu-
tional dynamics of alliance formation and interaction.
Structure? What structure? 95