We must consider the distinctive characters and the general nature of plants from the point of view of their morphology , their behavior under external conditions, their mode of generation, and the whole course of their life.

He knew that pearls came from Theophrastusll-fish that coral came from India and speaks of the fossilized remains of organic life. The book has been regarded by some as an independent work; others incline to the view that the sketches were written from time to time by Theophrastus and collected and edited after his death; others again regard the Characters as part of a larger systematic work but the style of the book is against this. The work contains thirty brief vigorous and trenchant outlines of moral types which form a most valuable picture of the life of his time and in fact of human nature in general.

". Aristotle bequeathed to Theophrastus his writings and designated him as his successor at the Lyceum. The interests of Theophrastus were wide ranging extending from biology and physics to ethics and metaphysics.