The movement is not at one step: it has a middle term or mean which often seems as if it were a step backward. Progress in knowledge is usually described as produced by the mode of demonstration or the mode of experience. Formal Logic prefers the first mode of describing it: Applied Logic prefers the second. Either mode may serve, if we properly comprehend what demonstration and experience mean. And that will not be done unless we keep equally before us the affirmative and the negative element in the process. The law of rational progress in knowledge, of the dialectical movement of consciousness, or in one word of experience, is not simple movement in a straight line, but movement by negation and absorption of the premisses. The conclusion or the new object of knowledge is a product into which the preceding object is reduced or absorbed. Thus the movement from faith (which is concentrated and wholly personal knowledge) to open and universal knowledge, which is capable of becoming the possession of a community,—truth and not merely conviction, must pass through doubt. The premisses from which we start, and the original object with which we begin, are not left in statu quo: they are destroyed in their own shape, and become only materials to build up a new object and a conclusion. It is on the stepping-stones of discarded ideas that we rise to higher truth: and it is on the abrogation of the old objects of knowledge that the new objects are founded. Not merely does a new object come in to supplement the old, and correct its inadequacies by the new presence: not merely do we add new ranges to our powers of vision, retaining the old faculties and subjoining others. The whole world—alike inward and outward,—the consciousness and its object—is subjected to a thorough renovation: every feature is modified, and the system re-created. The old perishes: but in perishing contributes to constitute the new. Thus the new is at once the affirmation and negation of the old. And such is the invariable nature of intelligent progress, of which the old and not a few modern logicians failed to render a right account, because they missed the negative element, and did not see that the immediate premisses must be abolished in order to secure a conclusion,—even as the grapes must be crushed before the wine can be obtained.

This is the real meaning of Experience, when it is called the teacher of humanity: and it was for this reason that Bacon described it as 'far the best demonstration.'[5] Experience is that absolute process, embracing both us and things, which displays the nullity of what is immediately given, or baldly and nakedly accepted, and completes it by the rough remedy of contradiction. The change comes over both us and the things: neither the one side nor the other is left as it was before. And it is here that the advantage of Experience over demonstration consists. Demonstration tends to be looked upon as subjective only (constringit assensum, non res): whereas Experience is also objective. But Experience is more than merely objective: it is the absolute process of thought pure and entire; and as such it is described by Hegel as Dialectic, or Dialectical movement. This Dialectic covers the ground of demonstration,—a fragment of it especially described and emphasised in the Formal Logic,—and of Experience,—under which name it is better known in actual life, and in the philosophy of the sciences[6].

Dialectic is the negative or destructive aspect of reason, as preparatory to its affirmative or constructive aspect. It is the spirit of dissent and criticism: the outgoing as opposed to the indwelling: the restless as distinguished from the quiet: the reproductive as opposed to the nutritive instinct: the centrifugal as opposed to the centripetal force: the radical and progressive tendency as opposed to the conservative. But no one of these examples sufficiently or accurately describes it. For it is the utterance of an implicit contradiction,—the recognition of an existing and felt, but hitherto unrecognised and unformulated want. Dialectic does not supervene from without upon the fixed ideas of understanding: it is the evidence of the higher nature which lies behind them, of the dependence on a larger unity which understanding implicitly or explicitly denies. That higher nature, the notion or grasp of reasonable thought, comes forward, and has at first, in opposition to the one-sided products of understanding, the look of a destructive agent. If we regard the understanding and its object, as ultimate and final,—and they are so regarded in the ordinary estimation of the world,—then this negative action of reason seems utterly pernicious, and tends to end in the subversion of all fixity whatever, of everything definite. In this light Dialectic is what is commonly known as Scepticism; just as the understanding in its excess is known as Dogmatism. But in the total grasp of the rational or speculative notion, Dialectic ceases to be Scepticism, and Understanding ceases to be Dogmatism.

Still there can be no doubt that the Dialectic of reason is dangerous, if taken abstractly and as if it were a whole truth. For the thoughts of ordinary men tend to be more abstract than their materials warrant. Men seek to formulate their feelings, faith, and conduct: but the rationale of their inmost belief,—their creed,—is generally narrower than it might be. Out of the undecomposed and massive 'substance,' on which their life and conduct is founded, they extract one or two ingredients: they emphasise with undue stress one or two features in their world, and attach to these partial formulae a value which would be deserved only if they really represented the whole facts. Hence when the narrow outlines of their creed are submitted to dialectic,—when the inlying contradictions are exposed, men feel as if the system of the world had sunk beneath them. But it is not the massive structure of their world, the organic unity in which they live, that is struck by dialectic: it is only those luminous points, the representative terms of material thought, which float before their consciousness, and which have been formulated in hard and fast outlines by the understanding. These points, as so defined and exaggerated, are what dialectic shakes. Not an alien force, but the inherent power of thought, destroys the temporary constructions of the understanding. The infinite comes to show the inadequacy of the finite which it has made.

In philosophy this second stage is as essential as the first. The one-sidedness of the first abstraction is corrected by the one-sidedness of the other. In the Philosophy of Plato, as has been noted, the dialectical energy of thought is sometimes spoken of under the analogy of sexual passion—the Love which, in the words of Sophocles, 'falls upon possessions' and makes all fixed ordinance of no account, and finds no obstacles insuperable to its strong desire. But Love, as the speaker explains, is a child of Wealth and Want: he is never poor, and never rich: he is in a mean between ignorance and knowledge[7]. Thus is described the active unrest of growth, the 'inquietude poussante,' as Leibniz called it,—the quickening force of the negative and of contradiction.

At the word 'contradiction' there is heard a murmur of objection, partly on technical, partly on material grounds. There are, it is said, other ways of getting from one idea to another than by contradiction: and it is not right to give the title to mere cases of contrast and correlation. Now it may be the case that the relations of ideas are many and various. In particular there is to many people a decided pleasure in the mere accumulation of bits of knowledge. In their mental stock there are only aggregates,—conjunctions due to accidents of time and place,—associations and fusions which do not reach organised unity. In all of us, perhaps, there are more or less miscellaneous collections of beliefs, perceptions, hopes, and wishes, in no very obvious connexion with one another. An united self, one, harmonious, and complete, is probably rather an ideal of development than a fact realised. There are in each two or three discordant selves,—among which it might sometimes be difficult to select the right and true one (for that will depend on the momentary point of view). The deeper consciousness may go on entirely independent of the train of the more superficial ideas: the world of reality may glide past without touching the world of dream or of fiction: our business part may live in a region parted off from our religion by gulfs inscrutable. In all these cases there cannot be said to be any contradiction.

But Hegel speaks of the essential progress of knowledge, and of that true self or real mind which has attained complete harmony—the self and mind that is implicitly or explicitly Absolute. In such a mind where the finite has passed or is passing into the infinite, in a mind that is really becoming one and total, its parts must meet and modify each other. At each phase, if that phase is earnest, self-certain, and real, it claims to be complete, and can brook no rival. The bringer of new things must appear as an enemy: for the old system, however imperfect as a mere form, has behind it the strength of an infinite and perfect content: it is more than it has explicated: but as it (from its imperfection and honesty) identifies itself with its form, it is resolved to resist change. Progress then must be by antagonism: it cannot be real progress otherwise, but only the mere shifting of dilettante doubt and dilettante toleration. Both new and old are worth something, and they must prove their value by neither being lost, but both recognised, in a completer scheme of things.

Yet there is a difference in the measure of contradiction at different stages of thought. It is always greatest when there is least to be opposed about. The more meagre an idea, a creed, a term of thought, the more violent the antitheses to it. The more abstractly we hold a doctrine, the more readily are we disposed to sniff opposition. And as in more concrete belief, so in the more abstract terms of thought. They seem so wide apart—like 'Is' and 'Is not'—and yet, taken alone, they are really so ready to recoil into one another. As thought deepens, contradiction takes a more modified form. The relativity of things becomes apparent: and what were erewhile opposed as contradictory, turn out as pairs of correlatives, neither of which is fully what it professed to be, unless it also is all that seemed reserved for the other. Lastly, and in the full truth of development, progress is seen to be not merely a sudden recoil from one abstraction to another, nor merely a continual reference to an underlying correlative, but the movement of one totality which advances by self-opposition, self-reconciliation, and self-reconstruction. In this stage, the weight and bulk of unity keeps the contradiction in its place of due subordination. But both elements are equally essential, and if the unity is less palpable in the abstract beginnings, and the divergence less wide at the close, at neither beginning nor close can either be absent.

But if we merely look at the differentiation or negation involved in the action of reason, we miss the half of its meaning: and the new statement is as one-sided as the old. We have not grasped the full meaning until we see that what, as understanding, affirmed a finite, denies, as dialectic, the absoluteness or adequacy of that finite. Both the partial views have a right to exist, because each gives its contribution to the science of truth.[8] If we penetrate behind the surface,—if we do not look at the two steps in the process abstractly and in separation,—it will be seen that these two elements coincide and unite. But we must be careful here. This coincidence or identification of opposites has not annihilated their opposition or difference. That difference subsists, but in abeyance, reduced to an element or 'moment' in the unity. Each of the two elements has been modified by the union: and thus when each issues from the unity it has a richer significance than it had before. This unity, in which difference is lost and found, is the rational notion,—the speculative grasp of thought. It is the product of experience,—the ampler affirmative which is founded upon an inclusion of negatives.

We began with the bare unit, or simple and unanalysed point, which satisfied popular language and popular imagination as its nucleus:—the representation which had caught and half-idealised a point, moment, or aspect in the range of feeling and sensation. In this stage the notion or thought proper is yet latent. In the first place, the nucleus of imagination was analysed, defined, and, as we may surmise, narrowed in the Intellect. And this grade of thought is known as the Understanding. In the second place, the definite and precise term, as understanding supposes it, was subjected to criticism: its contradictions displayed; and the very opposite of the first definition established in its place. This is the action of Dialectic. In the third place, by means of this second stage, the real nature or truth was seen to lie in a union where the opposites interpenetrate and mould each other. Thus we have as a conscious unity,—conscious because it, as unity, yet embraces a difference as difference—what we started with as an unconscious unity, the truth of feeling, faith, and inspiration. The first was an immediate unity:—that is to say, we were in the midst of the unity, sunk in it, and making a part of it: the second is a mediated unity, which has been reached by a process of reflection, and which as a conscious unity involves that process.