We can attend to the  
actual visual angles subtended  
by objects in the world by  
assuming a special attitude of  
the kind taken by artists.  
Usually this requires some  
effort on our part. However, in  
instances in which objects are  
seen at great distances or are  
extremely foreshortened, we  
often become spontaneously  
aware of the sizes of these  
angles. Thus, in driving down a  
road, we see the road’s edges as  
parallel, yet we are often aware  
at the same time that its sides  
converge toward the horizon.  
Later in the chapter I will  
discuss the significance of this  
subsidiary awareness we  
sometimes have of the actual  
visual angles formed by objects.  
However, although we can  
perceive objects as an artist  
does, these perceptions are not  
the central or most salient  
aspect of the way the world  
looks to us. That most salient  
aspect is constancy.