"You must develop your own powers." Mentor's thought was as final as fate. "Your mind is potentially far abler than mine. You will in time come to know my mind in full; I never will be able to know yours. For the lesser, but full mind to attempt to instruct in methodology the greater, although emptier one, is to set that greater mind in an under-sized mold and thus to do it irreparable harm. You have the abilities and the powers. You will have to develop them yourself, by the perfection of techniques concerning which I can give you no instructions whatever." "But surely you can give me some kind of a hint!" Kit pleaded. "I'm just a kid, I tell you--I don't even know how or where to begin!" Under Kit's startled mental gaze, Mentor split suddenly into four parts, laced together by a pattern of thoughts so intricate and so rapid as to be unrecognizable. The parts fused and again Mentor spoke. "I can point the way in only the broadest, most general terms. It has been decided, however, that I can give you one hint--or, more properly, one illustration. The surest test of knowledge known to us is the visualization of the Cosmic All. All science is, as you know, one. The true key to power lies in the knowledge of the underlying reasons for the succession of events. If it is pure causation--that is, if any given state of things follows as an inevitable consequence because of the state existing an infinitesimal instant before--then the entire course of the macrocosmic universe was set for the duration of all eternity in the instant of its coming into being. This well-known concept, the stumbling block upon which many early thinkers came to grief, we now know to be false. On the other hand, if pure randomness were to govern, natural laws as we know them could not exist. Thus neither pure causation nor pure randomness alone can govern the succession of events. "The truth, then, must lie somewhere in between. In the macro-cosmos, causation prevails; in the micro-, randomness; both in accord with the mathematical laws of probability. It is in the region between them--the intermediate zone, or the interface, so to speak--that the greatest problems lie. The test of validity of any theory, as you know, is the accuracy of the predictions which are made possible by its use, and our greatest thinkers have shown that the completeness and fidelity of any visualization of the Cosmic All are linear functions of the clarity of definition of the components of that interface. Full knowledge of that indeterminate zone would mean infinite power and a statistically perfect visualization. None of these things, however, will ever be realized; for the acquirement of that full knowledge would require infinite time. "That is all I can tell you. It will, properly studied, be enough. I have built within you a solid foundation; yours alone is the task of erecting upon that foundation a structure strong enough to withstand the forces which will be thrown against it.