  Santayana’s moral philosophy is based on his naturalism. Most commentators classify Santayana as an extreme moral relativist who maintains that all individual moral perspectives have equal standing and are based on the heritable traits and environmental circumstances of individuals. This naturalistic approach applies to all living organisms. Nature does not establish a moral hierarchy of goods between animal populations nor between individual animals. However, this same moral relativism is also the basis for Santayana’s claim that the good of individual animals is clear and is subject to naturalistic or biological investigation.