171 
arises from the impression which images make on the 
eye, or by an effusion of visual rays from the eye, as na¬ 
turalists contend, it is certain that, in some way or other, 
the eye is often deceived. Since, then, some images are 
falsely conveyed, and others appear different from what 
they really are, I think it beyond doubt, that, according 
to nature and the circumstances of the place, diminutions 
or additions should be made, so that no defect may be ap¬ 
parent. To do this, however, is the result of genius, not 
the result of learning. The proportion of the symmetries 
is, therefore, to be first settled, so that thereon the ne¬ 
cessary changes may be made with certainty. Then the 
length and breadth of the plan of the work is to be set 
out, and the parts thereof; after which, the proportions 
are adjusted as propriety requires, so that the pleasing 
arrangement may not be disturbed. The method of 
effecting this I am now about to describe, and shall 
begin with the court (cavæedium).