Evidence 91traces of its conception and implementation and all the
competing forces necessarily in play.
To what, Moulis asks, does this evidence add up? He
argues that, despite whatever interest Le Corbusier’s Adelaide
drawing might have as a curiosity and despite the context of
its production with Trumble in Bogotá, the Adelaide drawing
cannot be brought solidly to bear upon the analysis and
interpretation of Chandigarh’s design. Nevertheless, given
the similarity of the two documents and the proximity of
their production it legitimately works as a foil to the common
suite of references that explain the Punjab city’s origins.
In each of these instances evidence works conditionally to
undermine a given knowledge of the subject: the authorship
of San Lorenzo, the order of states in Piranesi’s Vedute, and
the origins of Le Corbusier’s Chandigarh. Cohen, Battaglia
and Moulis each resist unequivocal claims for the signifi cance
of their material other than to put new evidence into play
with old problems. Their combined effect – to which we can
add all other such efforts in the present-day fi eld of architec-
tural history – is to advance new knowledge while destabiliz-
ing the parameters of historical knowledge. As such, each in
their own way, they illustrate the claims famously made in
Carlo Ginzburg’s 1979 essay ‘Spie’ – a classic reading on the
nature and deployment of historical evidence.^12
The medical diagnostician has to reconcile the general and
typical presentations of a condition with its idiosyncratic
presentation in a specifi c patient. Historical problems in
architecture, as for any fi eld of historiography, inevitably fail
to manifest the same forms of evidence from case to case.
The evidentiary fi eld that attends to one historical problem,
therefore, is bound to differ in its utility or signifi cance from
the evidence that accumulates around another. This situation
calls for the historian to develop a diagnostician’s instinct
based on accumulated knowledge and intuition acquired over
time. Experience will inform the historian’s approach to the
inevitable negotiation between the particularities of a case
and its common characteristics. The architectural historian
has a sense of how things might have been in the setting of
his or her particular historical problem and draws on that
knowledge and experience to get from one secure footing to
the next and to propose (within reason, and limits) what