Sri Aurobindo uses the word atavism to denote a remnant from a previous stage of evolution. In other words, he uses it for habits and propensities that were useful and appropriate at some earlier stage, but that are not useful any longer and that have now, for us, become problematic. A typical example is desire: at an early stage of evolution, animals need desires to overcome the tamas, the laziness that is inherent in their physical nature, but humans can be driven into action by higher, more sophisticated motives.