Could Gandalf läsa sinne?

Det finns faktiskt ganska lite om "tanköverföring", inklusive dess begränsningar, i en uppsats med titeln "Ósanwe-kenta", daterad av Christopher Tolkien till 1959-1960 och första publicerad år 2000.

Uppsatsen är alldeles för lång att citera alla relevanta avsnitt, så jag begränsar mig till några av begränsningarna:

• Mottagandet måste vara "öppet":

  If we call one mind G (for guest or comer) and the other H (for host or receiver), then G must have full intention to inspect H or to inform it. But knowledge may be gained or imparted by G, even when H is not seeking or intending to impart or to learn: the act of G will be effective, if H is simply "open" (láta; látie “openness”). This distinction, he says, is of the greatest importance.

  "Openness" is the natural or simple state (indo) of a mind that is not otherwise engaged

• För inkarnater kräver överföring ytterligare förstärkning:

  The Incarnates have by the nature of sáma [mind] the same faculties; but their perception is dimmed by the hröa [body], for their fëa [spirit/soul] is united to their hröa and its normal procedure is through the hröa, which is in itself part of Eä, without thought. The dimming is indeed double; for thought has to pass one mantle of hröa and penetrate another. For this reason in Incarnates transmission of thought requires strengthening to be effective.

  Denna förstärkning kan härröra från affinitet mellan avsändare och mottagare, eller från brådskande eller auktoritet från avsändarens sida.

• Symbolisk kommunikation ( tengwesta ) gör det svårare:

  Lastly, tengwesta has also become an impediment. It is in Incarnates clearer and more precise than their direct reception of thought. By it also they can communicate easily with others, when no strength is added to their thought: as, for example, when strangers first meet. And, as we have seen, the use of "language" soon becomes habitual, so that the practice of ósanwe (interchange of thought) is neglected and becomes more difficult.

• Båda ovanstående är sanna även om Valar (och därmed förmodligen Maiar), men inte i samma grad, när de antar en kroppslig form:

  The hröa and tengwesta have inevitably some like effect upon the Valar, if they assume bodily raiment. The hröa will to some degree dim in force and precision the sending of the thought, and if the other be also embodied the reception of it. If they have acquired the habit of tengwesta, as some may who have acquired the custom of being arrayed, then this will reduce the practice of ósanwe. But these effects are far less than in the case of the Incarnate.