principle

1. a chemical component.

2. a substance on which certain of the properties of a drug depend.

3. an accepted or professed rule of action or conduct; in a given philosophical system it is a fundamental or general law or truth from which others are derived. In bioethics some important principles are beneficence, justice, nonmaleficence, and respect for autonomy; these are derived in part from professional roles and traditions.

active principle any constituent of a drug that helps to confer upon it a medicinal property.

Bobath p's a type of neurophysiological rehabilitation; see bobath method.

Bohr's principle of complementarity reflexes do not independently account for the complex nature of infant behavior.

negentropic principle a principle of general systems theory stating that open systems have mechanisms that slow down or arrest the process of movement toward less efficiency and growth. Negentropy (negative entropy) is the tendency toward order and organization.

pleasure principle (pleasure-pain principle) in psychoanalytic theory, an inborn tendency to avoid pain and seek pleasure through the immediate reduction of tension by either direct or fantasied gratification.

reality principle in psychoanalytic theory, the ego functions that modify the demands of the pleasure principle to meet the demands and requirements of the external world.