Contemporary esoteric systems almost always play on the desire of mankind to seek or acquire knowledge. All but universally neglected in such systems are the - often unrecognized - barriers which prevent knowledge and understanding. Before learning can take place, certain conditions and basic factors must be in place; in the individual or the group. Building on the foundations laid in Learning How to Learn and The Commanding Self, Idries Shah in Knowing How to Know illuminates those factors. Like an ultra-violet light shone onto the petals of flowers, it reveals concealed patterns, normally invisible to our customary modes of thought.