The Idea is the adequate Notion, that which is objectively true, or the true as such. When anything whatever possesses truth, it possesses it through its Idea, or, something possesses truth only in so far as it is Idea. The expression 'idea' has often been employed in philosophy as in ordinary life for 'notion', indeed, even for a mere ordinary conception: 'I have no idea yet of this lawsuit, building, neighbourhood', means nothing more than the ordinary conception. Kant has reclaimed the expression Idea for the notion of reason. Now according to Kant, the notion of reason is supposed to be the notion of the unconditioned, but a notion transcendent in regard to phenomena, that is, no empirical use can be made of such notion that is adequate to it. The notions of reason are to serve for the comprehension of perceptions, the notions of the understanding for understanding them. But in fact, if the latter really are Notions, then they are Notions — they enable one to comprehend, and an understanding of perceptions by means of notions of the understanding will be a comprehension of them. But if understanding is only a determining of perceptions by such categories as for example whole and parts, force, cause, and the like, it signifies only a determining by reflection; and similarly, by understanding can be meant only the specific representation of a completely determined sensuous content; thus when someone, having been directed that at the end of the wood he must turn left, replies 'I understand', understanding means nothing more than the grasping of something in pictorial thought and in memory. 'Notion of reason', too, is a somewhat clumsy expression; for the Notion is something altogether rational; and in so far as reason is distinguished from understanding and the Notion as such, it is the totality of the Notion and of objectivity. In this sense the Idea is the rational; it is the unconditioned, because only that has conditions which essentially relates itself to an objectivity, but an objectivity that it has not itself determined but which still confronts it in the form of indifference and externality, just as the external end still had conditions.
Reserving then the expression 'Idea' for the objective or real Notion and distinguishing it from the Notion itself and still more from mere pictorial thought, we must also reject even more vigorously that estimate of the Idea according to which it is not anything actual, and true thoughts are said to be only ideas. If thoughts are merely subjective and contingent, they certainly have no further value; but in this respect they are not inferior to temporal and contingent actualities which likewise have no further value than that of contingencies and phenomena. On the other hand if, conversely, the Idea is not to have the value of truth, because in regard to phenomena it is transcendent, and no congruent object can be assigned to it in the world of sense, this is an odd misunderstanding that would deny objective validity to the Idea because it lacks that which constitutes Appearance, namely, the untrue being of the objective world. In regard to practical Ideas, Kant recognises that 'nothing can be more harmful and unworthy of a philosopher than the vulgar appeal to an experience that allegedly conflicts with the Idea. This very experience would not even exist if, for example, political institutions had been established at the proper time in conformity with Ideas, and if crude conceptions, crude just because they had been drawn from experience, had not taken the place of Ideas and so nullified every good intention.' Kant regards the Idea as a necessity and as the goal which, as the archetype, it must be our endeavour to set up for a maximum and to which we must strive to bring the condition of the actual world ever nearer.
But having reached the result that the Idea is the unity of the Notion and objectivity, is the true, it must not be regarded merely as a goal to which we have to approximate but which itself always remains a kind of beyond; on the contrary, we must recognise that everything actual is only in so far as it possesses the Idea and expresses it. It is not merely that the object, the objective and subjective world in general, ought to be congruous with the Idea, but they are themselves the congruence of Notion and reality; the reality that does not correspond to the Notion is mere Appearance, the subjective, contingent, capricious element that is not the truth.
When it is said that no object is to be found in experience that is perfectly congruous with the Idea, one is opposing the Idea as a subjective standard to the actual; but what anything actual is supposed in truth to be, if its Notion is not in it and if its objectivity docs not correspond to its Notion at all, it is impossible to say; for it would be nothing. It is true that the mechanical and chemical object, like the nonspiritual subject and the spirit that is conscious only of the finite, not of its essence, do not, according to their various natures, have their Notion existent in them in its own free form. But they can only be true at all in so far as they are the union of their Notion and reality, of their soul and their body. Wholes like the state and the church cease to exist when the unity of their Notion and their reality is dissolved; man, the living being, is dead when soul and body are parted in him; dead nature, the mechanical and chemical world — taking, that is, the dead world to mean the inorganic world, otherwise it would have no positive meaning at all — dead nature, then, if it is separated into its Notion and its reality, is nothing but the subjective abstraction of a thought form and a formless matter. Spirit that was not Idea, was not the unity of the Notion with its own self, or the Notion that did not have the Notion itself for its reality would be dead, spiritless spirit, a material object.
The Idea being the unity of Notion and reality, being has attained the significance of truth; therefore what now is is only what is Idea. Finite things are finite because they do not possess the complete reality of their Notion within themselves, but require other things to complete it — or, conversely, because they are presupposed as objects, hence possess the Notion as an external determination. The highest to which they attain on the side of this finitude is external purposiveness. That actual things are not congruous with the Idea is the side of their finitude and untruth, and in accordance with this side they are objects, determined in accordance with their various spheres and in the relationships of objectivity, either mechanically, chemically or by an external end. That the Idea has not completely leavened its reality, has imperfectly subdued it to the Notion, this is a possibility arising from the fact that the Idea itself has a restricted content, that though it is essentially the unity of Notion and reality, it is no less essentially their difference; for only the object is their immediate, that is, merely implicit unity. But if an object, for example the state, did not correspond at all to its Idea, that is, if in fact it was not the Idea of the state at all, if its reality, which is the self-conscious individuals, did not correspond at all to the Notion, its soul and its body would have parted; the former would escape into the solitary regions of thought, the latter would have broken up into the single individualities.
But because the Notion of the state so essentially constitutes the nature of these individualities, it is present in them as an urge so powerful that they are impelled to translate it into reality, be it only in the form of external purposiveness, or to put up with it as it is, or else they must needs perish. The worst state, one whose reality least corresponds to the Notion, in so far as it still exists, is still Idea; the individuals still obey a dominant Notion.
However, the Idea has not merely the more general meaning of the true being, of the unity of Notion and reality, but the more specific one of the unity of subjective Notion and objectivity. That is to say, the Notion as such is itself already the identity of itself and reality; for the indefinite expression 'reality' means in general nothing else but determinate being, and this the Notion possesses in its particularity and individuality. Similarly too, objectivity is the total Notion that out of its determinateness has withdrawn into identity with itself. In the former subjectivity the determinateness or difference of the Notion is an illusory being [semblance] that is immediately sublated and has withdrawn into being-for-self or negative unity; it is an inhering predicate. But in this objectivity the determinateness is posited as an immediate totality, as an external whole. Now the Idea has shown itself to be the Notion liberated again into its subjectivity from the immediacy in which it is submerged in the object; to be the Notion that distinguishes itself from its objectivity, which however is no less determined by it and possesses its substantiality only in that Notion. 'This identity has therefore rightly been defined as the subject-object, for it is as well the formal or subjective Notion as it is the object as such. But this must be understood more precisely. The Notion, having truly attained its reality, is this absolute judgment whose subject, as self-related negative unity, distinguishes itself from its objectivity and is the latter's being-in-and-for-self, but essentially relates itself to it through itself; it is therefore its own end and the urge to realise it; but for this very reason the subject does not possess objectivity in an immediate manner, for if it did it would be merely the totality of the object as such lost in objectivity; on the contrary, objectivity is the realisation of the end, an objectivity posited by the activity of the end, an objectivity which, as positedness, possesses its subsistence and its form only as permeated by its subject. As objectivity, it has in it the moment of the externality of the Notion and is therefore in general the side of finitude, change and Appearance, a side, however, which meets with extinction in its retraction into the negative unity of the Notion; the negativity whereby its indifferent mutual externality exhibits itself as unessential and a positivity, is the Notion itself. The Idea is, therefore, in spite of this objectivity utterly simple and immaterial, for the externality exists only as determined by the Notion and as taken up into its negative unity; in so far as it exists as indifferent externality it is not merely at the mercy of mechanism in general but exists only as the transitory and untrue. Although therefore the Idea has its reality in a material externality, this is not an abstract being subsisting on its own account over against the Notion; on the contrary, it exists only as a becoming through the negativity of indifferent being, as a simple determinateness of the Notion.
This yields the following more precise definitions of the Idea. First, it is the simple truth, the identity of the Notion and objectivity as a universal in which the opposition and subsistence of the particular is dissolved into its self-identical negativity and is equality with itself. Secondly, it is the relation of the explicit subjectivity of the simple Notion and its objectivity which is distinguished therefrom; the former is essentially the urge to sublate this separation, and the latter is the indifferent positedness, the subsistence that is in and for itself null. As this relation, the Idea is the process of sundering itself into individuality and its inorganic nature, and again of bringing this inorganic nature under the power of the subject and returning to the first simple universality. The identity of the Idea with itself is one with the process; the thought which liberates actuality from the illusory show of purposeless mutability and transfigures it into the Idea must not represent this truth of actuality as a dead repose, as a mere picture, lifeless, without impulse or movement, as a genius or number, or an abstract thought; by virtue of the freedom which the Notion attains in the Idea, the Idea possesses within itself also the most stubborn opposition; its repose consists in the security and certainty with which it eternally creates and eternally overcomes that opposition, in it meeting with itself.
In the first instance, however, the Idea is once again only immediate or only in its Notion; objective reality is, it is true, conformable to the Notion, but it is not yet liberated into the Notion, and the latter does not exist explicitly for itself as Notion. Thus though the Notion is soul, it is soul in the guise of an immediate, that is, its determinateness does not appear as soul itself, it has not grasped itself as soul, it does not possess its objective reality within itself; the Notion is as a soul that is not yet fully a soul.
At this first stage the Idea is Life: the Notion that, distinguished from its objectivity, simple within itself, pervades its objectivity and, as its own end, possesses its means in the objectivity and posits the latter as its means, yet is immanent in this means and is therein the realised end that is identical with itself. This Idea, on account of its immediacy, has individuality for the form of its existence. But the reflection-into-self of its absolute process is the sublating of this immediate individuality; thereby the Notion which, as universality in this individuality, is the inwardness of the latter, converts the externality into universality, or posits its objectivity as being the same as itself.
In this second stage, the Idea is the Idea of the true and the good as cognition and volition. In the first instance, it is finite cognition and finite volition, in which the true and the good are still distinguished and each appears as yet only as a goal. The Notion has, in the first instance, liberated itself into itself and as yet given itself only an abstract objectivity for its reality. But the process of this finite cognition and action converts the initially abstract universality into a totality, whereby it becomes a complete objectivity. Or, to consider it from the other side, finite, that is, subjective spirit, makes for itself the presupposition of an objective world, just as life has such a presupposition; but its activity consists in sublating this presupposition and converting it into a positedness. In this way its reality is for it the objective world, or conversely, the objective world is the ideality in which it cognises itself.
Thirdly, spirit cognises the Idea as its absolute truth, as the truth that is in and for itself; the infinite Idea in which cognition and action are equalised, and which is the absolute knowledge of itself.