<p>The critically acclaimed novelist and social critic Aldous Huxley describes his personal experimentation with the drug mescaline and explores the nature of visionary experience. The title of this classic comes from William Blakes the Marriage of Heaven and Hell: If the doors of perception were cleansed every thing would appear to man as it is, infinite. For man has closed himself up, till he sees all things through narrow chinks of his cavern.</p>