ideology

n. [ Ideo- + -logy: cf. F. idéologie. ] 1. The science of ideas. Stewart. [ 1913 Webster ]

2. (Metaph.) A theory of the origin of ideas which derives them exclusively from sensation. [ 1913 Webster ]

☞ By a double blunder in philosophy and Greek, idéologie . . . has in France become the name peculiarly distinctive of that philosophy of mind which exclusively derives our knowledge from sensation. Sir W. Hamilton.

3. A set or system of theories and beliefs held by an individual or group, especially about sociopolitical goals and methods to attain them; in common usage, ideology is such a set of beliefs so strongly held by their adherents as to cause them to ignore evidence against such beliefs, and thus fall into error -- in this sense it is viewed as a negative trait; contrasted to pragmatism, and distinct from idealism. [ PJC ]