rly equivalent to _theory_, but is more frequently applied
to proposed action, and in the sense of a somewhat visionary plan. A
_speculation_ may be wholly of the brain, resting upon no facts worthy
of consideration; _system_ is the highest of these terms, having most of
assurance and fixity; a _system_ unites many facts, phenomena, or
doctrines into an orderly and consistent whole; we speak of a _system_
of theology, of the Copernican _system_ of the universe. Compare SYSTEM.

Antonyms:

certainty, demonstration, discovery, evidence, fact, proof.

* * * * *

IDEA.

Synonyms:

apprehension, design, impression, plan,
archetype, fancy, judgment, purpose,
belief, fantasy, model, sentiment,
conceit, ideal, notion, supposition,
concept, image, opinion, theory,
conception, imagination, pattern, thought.

_Idea_ is in Greek a _form_ or an _image_. The word signified in early
philosophical use the _archetype_ or primal _image_ which the Platonic
philosophy supposed to be the _model_ or _pattern_ that existing objects
imperfectly embody. This high sense has nearly disappeared from the word
_idea_, and has been largely appropriated by _ideal_, tho something of
the original meaning still appears when in theological or philosophical
language we speak of the _ideas_ of God. The present popular use of
_idea_ makes it to signify any product of mental _apprehension_ or
activity, considered as an object of knowledge or thought; this
coincides with the primitive sense at but a single point--that an _idea_
is mental as opposed to anything substantial or physical; thus, almost
any mental product, as a _belief_, _conception_, _design_, _opinion_,
etc., may now be called an _idea_. Compare FANCY; IDEAL.

Antonyms:

actuality, fact, reality, substance.

* * * * *

IDEAL.

Synonyms:

archetype, model, pattern, prototype, standard.
idea, original,

An _ideal_ is that which is conceived or taken as the highest type of
excellence or ultimate object of attainment. The _archetype_ is the
primal form, actual or imaginary, according to which any existing thing
is constructed; the _prototype_ has or has had actual existence; in the
derived sense, as in metrology, a _prototype_ may not be the original
form, but one having equal authority with that as a