To the development of Dialectic, as to God, intervals of time are of no account. From Plato and Aristotle we pass direct to Polybius.
The progress of thought from the philosopher of the Academe to the Arcadian historian may be best illustrated by a comparison of the method by which each of the three writers, whom I have selected as the highest expression of the rationalism of his respective age, attained to his ideal state: for the latter conception may be in a measure regarded as representing the most spiritual principle which they could discern in history.
Now, Plato created his on a priori principles; Aristotle formed his by an analysis of existing constitutions; Polybius found his realised for him in the actual world of fact. Aristotle criticised the deductive speculations of Plato by means of inductive negative instances, but Polybius will not take the ‘Cloud City’ of the Republic into account at all. He compares it to an athlete who has never run on ‘Constitution Hill,’ to a statue so beautiful that it is entirely removed from the ordinary conditions of humanity, and consequently from the canons of criticism.
The Roman state had attained in his eyes, by means of the mutual counteraction of three opposing forces, [59] that stable equilibrium in politics which was the ideal of all the theoretical writers of antiquity. And in connection with this point it will be convenient to notice here how much truth there is contained in the accusation often brought against the ancients that they knew nothing of the idea of Progress, for the meaning of many of their speculations will be hidden from us if we do not try and comprehend first what their aim was, and secondly why it was so.
Now, like all wide generalities, this statement is at least inaccurate. The prayer of Plato’s ideal City—ἐξ ἀγαθῶν ἀμείνους, καὶ ἐξ ὠφελιμῶν ὠφελιμωτέρους ἀεὶ τοὺς ἐκγόνους γίγνεσθαι, might be written as a text over the door of the last Temple to Humanity raised by the disciples of Fourier and Saint-Simon, but it is certainly true that their ideal principle was order and permanence, not indefinite progress. For, setting aside the artistic prejudices which would have led the Greeks to reject this idea of unlimited improvement, we may note that the modern conception of progress rests partly on the new enthusiasm and worship of humanity, partly on the splendid hopes of material improvements in civilisation which applied science has held out to us, two influences from which ancient Greek thought seems to have been strangely free. For the Greeks marred the perfect humanism of the great men whom they worshipped, by imputing to them divinity and its supernatural powers; while their science was eminently speculative and often almost mystic in its character, aiming at culture and not utility, at higher spirituality and more intense reverence for law, rather than at the increased facilities of locomotion and the cheap production of common things about which our modern scientific school ceases not to boast. And lastly, and perhaps chiefly, we must remember that the ‘plague spot of all Greek states,’ as one of their own writers has called it, was the terrible insecurity to life and property which resulted from the factions and revolutions which ceased not to trouble Greece at all times, raising a spirit of fanaticism such as religion raised in the middle ages of Europe.
These considerations, then, will enable us to understand first how it was that, radical and unscrupulous reformers as the Greek political theorists were, yet, their end once attained, no modern conservatives raised such outcry against the slightest innovation. Even acknowledged improvements in such things as the games of children or the modes of music were regarded by them with feelings of extreme apprehension as the herald of the drapeau rouge of reform. And secondly, it will show us how it was that Polybius found his ideal in the commonwealth of Rome, and Aristotle, like Mr. Bright, in the middle classes. Polybius, however, is not content merely with pointing out his ideal state, but enters at considerable length into the question of those general laws whose consideration forms the chief essential of the philosophy of history.
He starts by accepting the general principle that all things are fated to decay (which I noticed in the case of Plato), and that ‘as iron produces rust and as wood breeds the animals that destroy it, so every state has in it the seeds of its own corruption.’ He is not, however, content to rest there, but proceeds to deal with the more immediate causes of revolutions, which he says are twofold in nature, either external or internal. Now, the former, depending as they do on the synchronous conjunction of other events outside the sphere of scientific estimation, are from their very character incalculable; but the latter, though assuming many forms, always result from the over-great preponderance of any single element to the detriment of the others, the rational law lying at the base of all varieties of political changes being that stability can result only from the statical equilibrium produced by the counteraction of opposing parts, since the more simple a constitution is the more it is insecure. Plato had pointed out before how the extreme liberty of a democracy always resulted in despotism, but Polybius analyses the law and shows the scientific principles on which it rests.
The doctrine of the instability of pure constitutions forms an important era in the philosophy of history. Its special applicability to the politics of our own day has been illustrated in the rise of the great Napoleon, when the French state had lost those divisions of caste and prejudice, of landed aristocracy and moneyed interest, institutions in which the vulgar see only barriers to Liberty but which are indeed the only possible defences against the coming of that periodic Sirius of politics, the τύραννος ἐκ προστατικῆς ῥίζης.
There is a principle which Tocqueville never wearies of explaining, and which has been subsumed by Mr. Herbert Spencer under that general law common to all organic bodies which we call the Instability of the Homogeneous. The various manifestations of this law, as shown in the normal, regular revolutions and evolutions of the different forms of government, [63a] are expounded with great clearness by Polybius, who claimed for his theory, in the Thucydidean spirit, that it is a κτῆμα ἐς ἀεί, not a mere ἀγώνισμα ἐς τὸ παραχρῆμα, and that a knowledge of it will enable the impartial observer [63b] to discover at any time what period of its constitutional evolution any particular state has already reached and into what form it will be next differentiated, though possibly the exact time of the changes may be more or less uncertain. [63c]
Now in this necessarily incomplete account of the laws of political revolutions as expounded by Polybius enough perhaps has been said to show what is his true position in the rational development of the ‘Idea’ which I have called the Philosophy of History, because it is the unifying of history. Seen darkly as it is through the glass of religion in the pages of Herodotus, more metaphysical than scientific with Thucydides, Plato strove to seize it by the eagle-flight of speculation, to reach it with the eager grasp of a soul impatient of those slower and surer inductive methods which Aristotle, in his trenchant criticism of his greater master, showed were more brilliant than any vague theory, if the test of brilliancy is truth.