28 What is Architectural History?
authority over their time. Whereas these architects measured
in order to draw out more delicately the lessons antiquity
could offer contemporary architecture, the French scientist
and physician Claude Perrault (1613–88) understood that the
variation in the measurement of the orders found in Rome’s
buildings undermined any claim for natural authority that
might be made on their behalf. He wrote of ‘absolute beauty’
and ‘customary beauty’. For the former, the difference in
relative circumference between one column of the Doric
order and another worked against a universal standard for
beauty that anyone could appreciate. Architects could negoti-
ate these minor differences between the orders based on their
schooling in the classical tradition. In a customary beauty
might be found both the regularity of the orders and the
possibility of invention within them. For beauty to be avail-
able to all on the same terms required that scientifi c measure-
ment and a law of averages supplant the humanist tolerance
for variation negotiated by higher learning. To understand
this customary beauty within a tradition meant to understand
that it had changed over time.
In his treatise Ordonnance des cinq espèces de colonnes
selon la méthode des Anciens (1683), Perrault proposed a
new system of rules for the architectural orders based on
mean measurements of empirically derived proportions,
heights, circumferences and other data.^26 His method for
studying architectural history was no different from that used
to study natural history. He argued against the ‘rules’ of the
Greek and Roman orders. In his hands they became rational
systems of disposition, composition and ornamentation. He
demonstrated that it was possible to compose classical build-
ings on an empirical basis. The orders could be invoked
independent of the stories of their origin. Their authority was
historical, in relation to the known buildings of antiquity,
and not based on the mythology to which they supposedly
owed their beauty.
Greece versus Rome
Claude Perrault’s younger brother Charles perceived the
deeper philosophical implications of the problem that his