Donaldson set out to write the anti-Frodo, and has said so consistently: a protagonist who refuses the call, disbelieves the world he is in, and commits an unforgivable act in the first book. The debt is structural. The Land is a secondary world with its own geography and deep history; there is an ancient evil, a company that travels, and an object of power. Thomas Covenant is a leper from our world who treats all of it as a delusion, which only works as a device because the reader already knows the shape it is refusing. Filed as influence rather than reaction against: Donaldson credits Tolkien with making him want to write at all, and the inversion is of the hero, not of the form.