Full Idea
We do not see a tree exactly and entire with regard to its leaves, branches, colour and shape; it is so much easier for us to see an approximation of a tree.
Gist of Idea
We see an approximation of a tree, not the full detail
Source
Friedrich Nietzsche (Beyond Good and Evil [1886], §192)
Book Reference
Nietzsche,Friedrich: 'Beyond Good and Evil', ed/tr. Hollingdale,R.J. [Penguin 1973], p.97