If a person is not quite blind, that person often refuses to be led by a guide. Since he sees a little, he thinks it is best to go in whatever direction he can distinguish because he sees no better direction. So he can lead astray a guide who sees more than he, for after all, he tells the guide where to go. Also a soul may lean on any knowledge or feeling of its own. However great this knowledge might be, it is small and far different from what God is. A soul must pass beyond everything to unknowing.
-St. John of the Cross