It is fundamentally necessary, in order to avoid such floundering, that the "knowledge" of things sensible should be kept distinct from the "knowledge" of things spiritual; yet in practice they are constantly confused.
This fact, by itself, would go far to prove that the civilization continued fundamentally and essentially the same throughout.
Erigena argues the question entirely on speculative grounds, and starts with the bold affirmation that philosophy and religion are fundamentally one and the same- "Conficitur inde veram esse philosophiam veram religionem, conversimque veram religionem esse veram philosophiam."
Finally, side by side with a theory of the nature of moral obligation thus fundamentally empirical and a posteriori in its outlook, he maintains in his account of justice the existence of the idea of justice as distinct from a mere sentiment, carrying with it an a priori belief in its existence and identical in its a priori and intuitive character with the ultimate criterion of Utilitarianism itself.
Which, though they differ in details, are fundamentally ous in agreement.