An idea · Twentieth Century (to mid-century) · first attested 1900
Intentionality
Consciousness is always consciousness of something.
Borrowed from the medieval scholastic Brentano, sharpened by Husserl. Every mental act is directed at an object: belief is belief that, fear is fear of, desire is desire for. This object-directedness is the defining mark of the mental, and it is what makes a science of consciousness possible.