He represented, in an exceedingly adequate way, the progress of scientific method up to his day.

He was disciplined in all the natural science of his predecessors.

His judgment was an epitome of the scientific insight of the ages which culminated then.

The time was ripe for just such a great constructive thought as his--ripe, that is, so far as the accumulation of scientific data was concerned.

His judgment differed then from the judgment of his scientific contemporaries mainly in that it was sounder and safer than theirs.