The method of the Parmenides may be compared with the process of purgation, which Bacon sought to introduce into philosophy. Plato is warning us against two sorts of 'Idols of the Den': first, his own Ideas, which he himself having created is unable to connect in any way with the external world; secondly, against two idols in particular, 'Unity' and 'Being,' which had grown up in the pre-Socratic philosophy, and were still standing in the way of all progress and development of thought. He does not say with Bacon, 'Let us make truth by experiment,' or 'From these vague and inexact notions let us turn to facts.' The time has not yet arrived for a purely inductive philosophy. The instruments of thought must first be forged, that they may be used hereafter by modern inquirers. How, while mankind were disputing about universals, could they classify phenomena? How could they investigate causes, when they had not as yet learned to distinguish between a cause and an end? How could they make any progress in the sciences without first arranging them? These are the deficiencies which Plato is seeking to supply in an age when knowledge was a shadow of a name only. In the earlier dialogues the Socratic conception of universals is illustrated by his genius; in the Phaedrus the nature of division is explained; in the Republic the law of contradiction and the unity of knowledge are asserted; in the later dialogues he is constantly engaged both with the theory and practice of classification. These were the 'new weapons,' as he terms them in the Philebus, which he was preparing for the use of some who, in after ages, would be found ready enough to disown their obligations to the great master, or rather, perhaps, would be incapable of understanding them.
Numberless fallacies, as we are often truly told, have originated in a confusion of the 'copula,' and the 'verb of existence.' Would not the distinction which Plato by the mouth of Parmenides makes between 'One is one' and 'One has being' have saved us from this and many similar confusions? We see again that a long period in the history of philosophy was a barren tract, not uncultivated, but unfruitful, because there was no inquiry into the relation of language and thought, and the metaphysical imagination was incapable of supplying the missing link between words and things. The famous dispute between Nominalists and Realists would never have been heard of, if, instead of transferring the Platonic Ideas into a crude Latin phraseology, the spirit of Plato had been truly understood and appreciated. Upon the term substance at least two celebrated theological controversies appear to hinge, which would not have existed, or at least not in their present form, if we had 'interrogated' the word substance, as Plato has the notions of Unity and Being. These weeds of philosophy have struck their roots deep into the soil, and are always tending to reappear, sometimes in new-fangled forms; while similar words, such as development, evolution, law, and the like, are constantly put in the place of facts, even by writers who profess to base truth entirely upon fact. In an unmetaphysical age there is probably more metaphysics in the common sense (i.e. more a priori assumption) than in any other, because there is more complete unconsciousness that we are resting on our own ideas, while we please ourselves with the conviction that we are resting on facts. We do not consider how much metaphysics are required to place us above metaphysics, or how difficult it is to prevent the forms of expression which are ready made for our use from outrunning actual observation and experiment.
In the last century the educated world were astonished to find that the whole fabric of their ideas was falling to pieces, because Hume amused himself by analyzing the word 'cause' into uniform sequence. Then arose a philosophy which, equally regardless of the history of the mind, sought to save mankind from scepticism by assigning to our notions of 'cause and effect,' 'substance and accident,' 'whole and part,' a necessary place in human thought. Without them we could have no experience, and therefore they were supposed to be prior to experience—to be incrusted on the 'I'; although in the phraseology of Kant there could be no transcendental use of them, or, in other words, they were only applicable within the range of our knowledge. But into the origin of these ideas, which he obtains partly by an analysis of the proposition, partly by development of the 'ego,' he never inquires—they seem to him to have a necessary existence; nor does he attempt to analyse the various senses in which the word 'cause' or 'substance' may be employed.
The philosophy of Berkeley could never have had any meaning, even to himself, if he had first analyzed from every point of view the conception of 'matter.' This poor forgotten word (which was 'a very good word' to describe the simplest generalization of external objects) is now superseded in the vocabulary of physical philosophers by 'force,' which seems to be accepted without any rigid examination of its meaning, as if the general idea of 'force' in our minds furnished an explanation of the infinite variety of forces which exist in the universe. A similar ambiguity occurs in the use of the favourite word 'law,' which is sometimes regarded as a mere abstraction, and then elevated into a real power or entity, almost taking the place of God. Theology, again, is full of undefined terms which have distracted the human mind for ages. Mankind have reasoned from them, but not to them; they have drawn out the conclusions without proving the premises; they have asserted the premises without examining the terms. The passions of religious parties have been roused to the utmost about words of which they could have given no explanation, and which had really no distinct meaning. One sort of them, faith, grace, justification, have been the symbols of one class of disputes; as the words substance, nature, person, of another, revelation, inspiration, and the like, of a third. All of them have been the subject of endless reasonings and inferences; but a spell has hung over the minds of theologians or philosophers which has prevented them from examining the words themselves. Either the effort to rise above and beyond their own first ideas was too great for them, or there might, perhaps, have seemed to be an irreverence in doing so. About the Divine Being Himself, in whom all true theological ideas live and move, men have spoken and reasoned much, and have fancied that they instinctively know Him. But they hardly suspect that under the name of God even Christians have included two characters or natures as much opposed as the good and evil principle of the Persians.
To have the true use of words we must compare them with things; in using them we acknowledge that they seldom give a perfect representation of our meaning. In like manner when we interrogate our ideas we find that we are not using them always in the sense which we supposed. And Plato, while he criticizes the inconsistency of his own doctrine of universals and draws out the endless consequences which flow from the assertion either that 'Being is' or that 'Being is not,' by no means intends to deny the existence of universals or the unity under which they are comprehended. There is nothing further from his thoughts than scepticism. But before proceeding he must examine the foundations which he and others have been laying; there is nothing true which is not from some point of view untrue, nothing absolute which is not also relative (compare Republic).
And so, in modern times, because we are called upon to analyze our ideas and to come to a distinct understanding about the meaning of words; because we know that the powers of language are very unequal to the subtlety of nature or of mind, we do not therefore renounce the use of them; but we replace them in their old connexion, having first tested their meaning and quality, and having corrected the error which is involved in them; or rather always remembering to make allowance for the adulteration or alloy which they contain. We cannot call a new metaphysical world into existence any more than we can frame a new universal language; in thought as in speech, we are dependent on the past. We know that the words 'cause' and 'effect' are very far from representing to us the continuity or the complexity of nature or the different modes or degrees in which phenomena are connected. Yet we accept them as the best expression which we have of the correlation of forces or objects. We see that the term 'law' is a mere abstraction, under which laws of matter and of mind, the law of nature and the law of the land are included, and some of these uses of the word are confusing, because they introduce into one sphere of thought associations which belong to another; for example, order or sequence is apt to be confounded with external compulsion and the internal workings of the mind with their material antecedents. Yet none of them can be dispensed with; we can only be on our guard against the error or confusion which arises out of them. Thus in the use of the word 'substance' we are far from supposing that there is any mysterious substratum apart from the objects which we see, and we acknowledge that the negative notion is very likely to become a positive one. Still we retain the word as a convenient generalization, though not without a double sense, substance, and essence, derived from the two-fold translation of the Greek ousia.
So the human mind makes the reflection that God is not a person like ourselves—is not a cause like the material causes in nature, nor even an intelligent cause like a human agent—nor an individual, for He is universal; and that every possible conception which we can form of Him is limited by the human faculties. We cannot by any effort of thought or exertion of faith be in and out of our own minds at the same instant. How can we conceive Him under the forms of time and space, who is out of time and space? How get rid of such forms and see Him as He is? How can we imagine His relation to the world or to ourselves? Innumerable contradictions follow from either of the two alternatives, that God is or that He is not. Yet we are far from saying that we know nothing of Him, because all that we know is subject to the conditions of human thought. To the old belief in Him we return, but with corrections. He is a person, but not like ourselves; a mind, but not a human mind; a cause, but not a material cause, nor yet a maker or artificer. The words which we use are imperfect expressions of His true nature; but we do not therefore lose faith in what is best and highest in ourselves and in the world.
'A little philosophy takes us away from God; a great deal brings us back to Him.' When we begin to reflect, our first thoughts respecting Him and ourselves are apt to be sceptical. For we can analyze our religious as well as our other ideas; we can trace their history; we can criticize their perversion; we see that they are relative to the human mind and to one another. But when we have carried our criticism to the furthest point, they still remain, a necessity of our moral nature, better known and understood by us, and less liable to be shaken, because we are more aware of their necessary imperfection. They come to us with 'better opinion, better confirmation,' not merely as the inspirations either of ourselves or of another, but deeply rooted in history and in the human mind.