Abstract: Collingwood, a prominent philosopher of history, claims that a defect in Greek and Roman Historiography is substantialism, which is based on the concept of substance in Plato and Aristotle. According to Collingwood, substantialism has determined the way to describe Rome in Livy so that it remains eternal from the very beginning of its foundation with distinctive institutions and unique spirits. However, Livy’s Ab Urbe Condita shows how Rome changed from her beginning to Livy’s own age. Augury, senate, legion and other institutions were in the course of evolution, and Roman virtues declined with the accumulated wealth from abroad. In effect, Livy understands history in an evolutional way.