Students of perception, 
therefore, have advanced 
beyond the global, all-or-
nothing Nativism-Empiricism 
controversy. Instead of asking 
whether space perception is 
learned or innate, they now 
approach the issue in more 
specific terms. Is this or that 
cue learned? It is plausible to 
assume that some cues have an 
innate significance while 
others come to indicate 
distance and depth because 
they happen to be present in 
the stimulus along with innate 
cues. This approach permits us 
to see that the perceptual 
system can be more easily 
modified than the Nativists 
recognized. On the other hand, 
the Empiricists had no way of 
explaining how learning could 
occur except by retreating to 
other sense modalities. This 
approach permits an 
alternative explanation.

The discussion of constancy in 
the previous chapter and of 
pictorial cues to depth in this 
one provides the necessary 
background for a discussion of 
the perception and creation of 
pictures. It is to these topics, 
considered as part of the 
broader problem of perception 
and art, that I turn in Chapter 
4.