Full Idea
What the eye, the ear, or the hand feels, is not perception, it is merely data. Only when the understanding passes from the effect to the cause does the world lie before us as perception extended in space.
Gist of Idea
Direct feeling of the senses are merely data; perception of the world comes with understanding causes
Source
Arthur Schopenhauer (The World as Will and Idea [1819], I 004)
Book Reference
Schopenhauer,Arthur: 'The World as Will and Idea', ed/tr. Berman,Jill and David [Everyman 1995], p.9
A Reaction
These certainly seems to be a sense-data theory. Philosophers are much more ready to separate the data from the understanding than neuroscientists are.