@sometime sun,
Beauty may not be truth itself, but it is definitely borne out of the search for truth...
Look at all the great artists, starting with Cezane, he desperately wanted to find a way of representing reality, but he knew that 'the perceived contains the perceiver' (i.e. we can never know true reality because we each impart some of our own conceptual scheme - as Kant would say - on our view of the world). However, he eventually came to the view that the truth lies in geometric objects such as cubes, spheres, which - he thought - did not differ from person to person depending on each one's perception, hence the routes of Cubism.
In this way it seems that art and philosophy are closely linked, purely because, at the heart of both disciplines, lies the search for truth
(I am no art historian, this is just from what I have read, so apologies for any errors!)