theory - a well-substantiated explanation of some aspect of the natural world; an organized system of accepted knowledge that applies in a variety of circumstances to explain a specific set of phenomena; "theories can incorporate facts and laws and tested hypotheses"; "true in fact and theory"

organicism - theory that the total organization of an organism rather than the functioning of individual organs is the determinant of life processes

configurationism, Gestalt psychology - (psychology) a theory of psychology that emphasizes the importance of configurational properties