Spencer Herbert (1820–1903), English philosopher, social reformer, and editor of The Economist. In epistemology, Spencer adopted the nineteenth-century trend toward positivism: the only reliable knowledge of the universe is to be found in the sciences. His ethics were utilitarian, following Bentham and J. S. Mill: pleasure and pain are the criteria of value as signs of happiness or unhappiness in the individual. His Synthetic Philosophy, expounded in books written over many years, assumed (both in biology and psychology) the existence of Lamarckian evolution: given a characteristic environment, every animal possesses a disposition to make itself into what it will, failing maladaptive interventions, eventually become. The dispositions gain expression as inherited acquired habits. Spencer could not accept that species originate by chance variations and natural selection alone: direct adaptation to environmental constraints is mainly responsible for biological changes. Evolution also includes the progression of societies in the direction of a dynamical equilibrium of individuals: the human condition is perfectible because human faculties are completely adapted to life in society, implying that evil and immorality will eventually disappear. His ideas on evolution predated publication of the major works of Darwin; A. R. Wallace was influenced by his writings. R.E.B.