idea

My dialectical method is, in its foundations, not only different from the Hegelian, but exactly opposite to it. For Hegel, the process of thinking, which he even transforms into an independent subject, under the name of 'the idea', is the creator of the real world, and the real world is only the external appearance of the idea. With me, the reverse is true: the ideal is nothing but the material world reflected in the mind of man, and translated into forms of thought." Karl Marx, Capital, vol. 1,Preface to the Second Edition. (p.102) (see ideal / real ) 

introduce: Platonic ideas (forms) with autonomous existence
Freudian relation of ideas to cathexis (esp. repression / defense)
Deleuzian "affective force" 

In the Critique of Judgement, Kant describes aesthetical ideas as "representations of the imagination which occasion much thought, without however any definite thought, i.e. any concept being capable of being adequate to them. An aesthetic idea, whicch cannot be completely compassed and made intelligible by language, is the counterpart of a rational idea of the understanding, to which no intuition (or representation of the imagination) is adequate. (p. 157)