custom supersedes any trace of thought which might transcend it. The species sinks into a stationary stage in which thought is canalized between the banks of custom.
The history of the speculative Reason is altogether shorter. It belongs to the history of civilization, and its span is about six thousand years. But the critical discovery which gave to the speculative Reason its supreme importance was made by the Greeks. Their discovery of mathematics and of logic introduced method into speculation. Reason was now armed with an objective test and with a method of progress. In this way Reason was freed from its sole dependence on mystic vision and fanciful suggestion. Its method of evolution was derived from itself. It ceased to produce a mere series of detached judgments. It produced systems instead of inspirations. The speculative Reason armed with the Greek methods, is older than two thousand years only by a few centuries.
The ascription of the modern phase of the speculative Reason wholly to the Greeks, is an exaggeration. The great Asiatic civilizations, Indian and Chinese, also produced variants of the same method. But none of these variants gained the perfected technique of the Greek method. Their modes of handling speculative Reason were effective for the abstract religious speculation, and for philosophical speculation, but failed before natural science and mathematics. The Greeks produced the final instrument for the discipline of speculation.