For the catastrophe will have to have been of such a kind that it was not and has not been—except perhaps by a very few—recognized as a catastrophe. We shall have to look not for a few brief striking events whose character is incontestably clear, but for a much longer, more complex and less easily identified process and probably one which by its very nature is open to rival interpretation. Yet the initial implausibility of this part of the hypothesis may perhaps be slightly lessened by another suggestion.
