Griffin was not a telepath in the sense that the S.M.M.R. used the word, but to a non-psionicist, he would have appeared to be one. Membership in the "core" group of the _Society for Mystical and Metaphysical Research_ required, above all, _understanding_. And, with that understanding, a conversation between two members need consist only of an occasional gesture and a key word now and then. The word "understanding" needs emphasis. Without understanding of another human mind, no human mind can be completely effective. Without that understanding, no human being can be completely free. And yet, the English word "understanding" is only an approximation to the actual process that must take place. _Total_ understanding, in one sense, would require that a person actually _become_ another person--that he be able to feel, completely and absolutely, every emotion, every thought, every bodily sensation, every twinge of memory, every judgment, every decision, and every sense of personal identity that is felt by the other person, no more and no less. Such totality is, obviously, neither attainable nor desirable. The result would be a merger of identities, a total unification. And, as a consequence, a complete loss of one of the human beings involved. Optimum "understanding" requires that a judgment be made, and that, in turn, requires _two_ minds--not a fusion of identity. There must be one to judge and another to be judged, and each mind plays both roles. _Love thy neighbor as thyself._ But the original Greek word would translate better as "respect and understand" than as the modern English "love." The founders of our modern religions were not fools; they simply did not have the tools at hand to formulate their knowledge properly. As understanding increases, a critical point is reached, which causes a qualitative change in the human mind. First, self-understanding must come. The human mind operates through similarities, and the thing most similar to any human mind is itself. The next most similar thing is another human mind. From that point on, all objects, processes, and patterns in the universe can be graded according to their similarity to each other, and, ultimately, to their similarity to the human mind. Two given entities may seem utterly dissimilar, but they can always be linked by a _tertium quid_--a "third thing" which is similar to both. This third thing, be it a material object or a product of the human imagination, is called a symbol. Symbols are the bridges by which the human mind can reach and manipulate the universe in which it exists. With the proper symbols and the understanding to use them, the human mind is limited only by its own inherent structural restrictions.