How then can we arrive at any ethical rule by the study of Biology? In this way. An organism is a moving equilibrium: it is a law of moving equilibria that they counterbalance by means of new adjustments antagonistic forces in the environment, and absorb forces from the environment favourable to their continuance. Their continued existence depends upon such continuous absorption and adjustment. But as environment varies, so do adjustments; and thus there is a wonderful variety of different moving equilibria, which form important parts of one another's environment. The suitable structures and functions which have thus been evolved are therefore relative to the environment, and the inherited structure and functions forming a moving equilibrium are fitted for particular environments and no other. There is no absolute moving equilibrium; all are relative. "That which was defined as a moving equilibrium, we define biologically as a balance of functions. The implication of such a balance is that the several functions in their kinds, amounts, and combinations, are adjusted to the several activities which maintain and constitute complete life; and to be so adjusted is to have reached the goal towards which the evolution of conduct continually tends." But completeness of life means primarily the completeness of life in each individual organism as regards its continued existence, and the full satisfaction of all its functions during the period of its existence. The biologically good is all that conduces to this end, and the biologically bad is all that detracts from it. The biologically good and bad are therefore relative to the consensus of functions which constitute an animal or other organism. The biologically good and bad are therefore individual. That which is good for the individual is the right conduct, and that which is bad for it is wrong conduct. It is therefore right for the big fishes to eat the little ones, for the bird to prey upon the insect; it is a fit satisfaction for the functions of the lion to devour the antelope, for one tribe to slay or drive out another tribe in order to possess itself of more fertile plains and more delightful countries. And so, as long as the functions delight in egoism, and there is no counterforce of sympathy included among them, it is right to tyrannise, to subject others to the service or passions of the dominant organisms. They subserve the biological law--they are conducive to complete relative life. The biological law does not recognise the lives of others until sympathy has become part of the functions of the organism.