Instruct: Classify a given Amazon review as either positive or negative.
Query: A keeper

Fine reference with long enough articles to engage but not overwhelm. Three well- qualified authors, including the late Roy Porter (historian of medicine & culture) combine efforts. Philosophy & social sciences included, e.g. "phenomenology" and "psychotherapy" and "soul." Biographical index briefly identifies hundreds of scientists, philosophers and historians. Now 25 years old but still valuable.