  Two tenets of his ethics are (1) the forms of the good are diverse, and (2) the good of each animal is definite and final. The moral terrain of animals, viewed from a neutral perspective, places all animal interests and goods as equal. Each good stems from heritable physical traits and is shaped by adaptations to the environment. Concluding that the “forms of the good are divergent,” Santayana holds that the good for each animal may differ, depending on the nature of the psyche and the circumstances, and may be different for an individual animal in different times and environments. There is no one good for all, or even for an individual.