Philosopy vs Psychology in Art

Hi all,
I have a question that is pestering me since years.

Why seems Philosophy more valid than Psychology in the Art practice?
(the answer that both are valid in the same way doesn't seem to hold up. And please don't suggest to work in the field of psychology - because that is escapism and doesn't satisfy me)

Psychology has always intrigued me more and interested me more than Philosophy. Always when I referenced Psychology I got a slap on my hand that I needed more Philosophy to back my practice up. History has been a very important aspect to my work as well - so why does Philosophy seem to occupy the throne in the reputable world of art making???

:-/ Biggi