“Not from men as an ultimate, nor through man as a mediate authority.”—Ellicott. “In the first clause, ‘from men,’ he distinguishes himself from the false apostles who did not derive their authority from God at all; in the second, ‘through man,’ he ranks himself with the twelve who were commissioned directly from God. The singular is used in second clause, ‘through man,’ because offices which emanate from a body of men are conferred by their single representative.”—Lightfoot. [“Paul has in second clause used the singular because the contrast is ‘through Jesus Christ.’”—Meyer.—G.A.]