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.

Prolegomena to the Study of Hegel's Philosophy — Part 202