Possibilist Knowledge: A Rigorous Framework for an Indeterminist Science

Possibilist knowledge is the kind of scientific knowledge about what makes something possible or impossible in a given context, given the satisfaction or absence of a necessary condition, and which is formed by possibilist laws and explanations. This formulation addresses the tension between a natural world ruled by natural laws and a social world filled with agents endowed with some degree of freedom. Gustavo Casta隳n explores consequencesof such a knowledge in the nature of scientific explanation and of scientific psychology, arguing that a true complete scientific explanation should be causal and law based; that a mechanism performs a function; and that only possibilist and comparative ceteris paribus laws are the only forms we can expect from scientific psychology and every prediction or explanation that sufficiently predict or explain a psychological phenomenon is philosophical and unfalsifiable. Finally, the author argues that possibilist knowledge is compatible with beliefs in incompatibilism, with free will, and with a universe regulated by strict laws.