HELP!! Cant find the quote I need!!

Bookworms of DV I need your help!!!

I am sure in one of the books by Laberge or Waggoner is a quote from a famous psychologist who says something like :

We will have completed our exploration of the galaxy long before we finish exploring the mind.

Does anyone know the correct quote? Who said it? or what book(chapter/page) its in?

Thanks - Im writing an article for a journal I contribute to on Lucid dreaming and also giving a series of public lectures and I would love to use the proper quote and source.