IDE'A, n. [L. idea; Gr. to see, L. video.]

1. Literally, that which is seen; hence, form, image, model of any thing in the mind; that which is held or comprehended by the understanding or intellectual faculties. I have used the word idea, to express whatever is meant by phantasm, notion, species, or whatever it is which the mind can be employed about in thinking. Locke. Whatever the mind perceives in itself, or is the immediate object of perception, thought or understanding, that I call an idea. Locke. The attention of the understanding to the objects acting on it, by which it becomes sensible of the impressions they make, is called by logicians, perception; and the notices themselves as they exist in the mind, as the materials of thinking and knowledge, are distinguished by the name of ideas. Encyc. art. Logic. An idea is the reflex perception of objects, after the original perception or impression has been felt by the mind. Encyc. In popular language, idea signifies the same thing as conception, apprehension, notion. To have an idea of any thing is to conceive it. In philosophical use, it does not signify that act of the mind which we call thought or conception, but some object of thought. Reid. According to modern writers on mental philosophy, an idea is the object of thought, or the notice which the mind takes of its perceptions. Darwin uses idea for a notion of external things which our organs bring us acquainted with originally, and he defines it, a contraction, motion or configuration of the fibers which constitute the immediate organ of sense; synonymous with which he sometimes uses sensual motion, in contradistinction to muscular motion.
2. In popular use, idea signifies notion, conception, thought, opinion, and even purpose or intention. Burke.
3. Image in the mind. Her sweet idea wandered through his thoughts. Fairfax. [A bad use of the word.]
4. An opinion, a proposition. These decisions are incompatible with the idea, that the principles are derived from the civil law.

1. The transcript, image, or picture of a visible object, that is formed by the mind; also, a similar image of any object whatever, whether sensible or spiritual.
   
   

   Her sweet idea wandered through his thoughts. Fairfax.

   Being the right idea of your father
   Both in your form and nobleness of mind. Shak.

   This representation or likeness of the object being transmitted from thence [the senses] to the imagination, and lodged there for the view and observation of the pure intellect, is aptly and properly called its idea. P. Browne.

2. A general notion, or a conception formed by generalization.
   
   

   Alice had not the slightest idea what latitude was. L. Caroll.

3. Hence: Any object apprehended, conceived, or thought of, by the mind; a notion, conception, or thought; the real object that is conceived or thought of.
   
   

   Whatsoever the mind perceives in itself, or as the immediate object of perception, thought, or undersanding, that I call idea. Locke.

4. A belief, option, or doctrine; a characteristic or controlling principle; as, an essential idea; the idea of development.
   
   

   That fellow seems to me to possess but one idea, and that is a wrong one. Johnson.

   What is now "idea" for us? How infinite the fall of this word, since the time where Milton sang of the Creator contemplating his newly-created world, -
   "how it showed . . .
   Answering his great idea," -
   to its present use, when this person "has an idea that the train has started," and the other "had no idea that the dinner would be so bad!" Trench.

5. A plan or purpose of action; intention; design.
   
   

   I shortly afterwards set off for that capital, with an idea of undertaking while there the translation of the work. W. Irving.

6. A rational conception; the complete conception of an object when thought of in all its essential elements or constituents; the necessary metaphysical or constituent attributes and relations, when conceived in the abstract.
7. A fiction object or picture created by the imagination; the same when proposed as a pattern to be copied, or a standard to be reached; one of the archetypes or patterns of created things, conceived by the Platonists to have excited objectively from eternity in the mind of the Deity.
   
   

   Thence to behold this new-created world,
   The addition of his empire, how it showed
   In prospect from his throne, how good, how fair,
   Answering his great idea. Milton.

   * "In England, Locke may be said to have been the first who naturalized the term in its Cartesian universality. When, in common language, employed by Milton and Dryden, after Descartes, as before him by Sidney, Spenser, Shakespeare, Hooker, etc., the meaning is Platonic." Sir W. Hamilton.

   Abstract idea, Association of ideas, etc. See under Abstract, Association, etc.

   Syn. -- Notion; conception; thought; sentiment; fancy; image; perception; impression; opinion; belief; observation; judgment; consideration; view; design; intention; purpose; plan; model; pattern. There is scarcely any other word which is subjected to such abusive treatment as is the word idea, in the very general and indiscriminative way in which it is employed, as it is used variously to signify almost any act, state, or content of thought.