Concepts are, so to speak, problem-solving devices, the internal equivalent of technologies; they are the technologies of the mind-machine. Concepts, theories, hypotheses, distinctions, comparisons—all these may be taken ultimately as instruments for organizing perceptions into logically consistent patterns called explanations. But they do not and cannot awaken in man a new quality of feeling or perceiving, a new organ or faculty of awareness. Concepts are no more nor less than tools by which man combines or analyzes that which he already knows through perceptions. If man's perceptions are limited mainly to the external senses, concepts can do no more than organize the material collected by the senses. Concepts can never reach beyond the level of perception at which man lives. Ideas, on the other hand, evoke, support, and require a higher level of awareness itself.