memetic originality
Ideas have a life of their own, and are subject to the same evolutionary dynamics that govern biological systems. The current state of development together with the current environmental context determines more or less what the next stage of development will be. Our most original ideas are either juxtapositions of some old material, or reactionary moves taken against some environmental changes.
Even if the next step is not obvious from our local point of view, it always is so from the global point of view. The society as a whole will sooner or later give birth to the next new idea. It may be impossible to predict its author, but so what? That is not a societal concern.
As Victor Hugo said, "there is nothing more powerful than an idea whose time has come." All we have to do is to open our mouth or grab a pen.
Every once in a while a particular species will evolve too fast for its own good. Anticipating and adopting the far future can be a costly activity. Authors that are too out-of-sync with the general flow of ideas will be doomed to oblivion until the time for their products finally arrive.