Jung spent the better part of the end of his life studying the subject of alchemy, which has been called the search for the godhead in matter. In typical "Jungian" style, his interest in alchemy developed from a vivid dream about an ancient library full of arcane books. Later, after much searching, Jung came to posses such a library. Alchemy reflected in symbolic form the same sorts of imagery Jung saw in his practice in neurosis, psychosis, dreams and imagination. Jung insisted that the psyche cannot be understood in conceptual terms, but only through living images or symbols, which are able to contain paradox and ambiguity. Alchemy reflects the process of personal transformation in the metaphor of transmuting base metals into gold.