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The concept of progress

He gives the analogy an anthropological twist and introduces the comparative method coming into vogue in other disciplines. Lewis names units called ethna, by which he means inventions, discoveries and domestic institutions. The ethna are compared and judged higher or lower on the scale, pair by pair. Morgan's ethna appear to comprise at least some of Edward Burnett Tylor 's cultural objects. Morgan mentions Tylor a number of times in the book.