Theaetetus

Plato, in the spirit of the Megarian philosophy, soon discovers a flaw in the explanation. For how can we know a compound of which the simple elements are unknown to us? Can two unknowns make a known? Can a whole be something different from the parts? The answer of experience is that they can; for we may know a compound, which we are unable to analyze into its elements; and all the parts, when united, may be more than all the parts separated: e.g. the number four, or any other number, is more than the units which are contained in it; any chemical compound is more than and different from the simple elements. But ancient philosophy in this, as in many other instances, proceeding by the path of mental analysis, was perplexed by doubts which warred against the plainest facts.

Three attempts to explain the new definition of knowledge still remain to be considered. They all of them turn on the explanation of logos. The first account of the meaning of the word is the reflection of thought in speech – a sort of nominalism 'La science est une langue bien faite.' But anybody who is not dumb can say what he thinks; therefore mere speech cannot be knowledge. And yet we may observe, that there is in this explanation an element of truth which is not recognized by Plato; viz. that truth and thought are inseparable from language, although mere expression in words is not truth. The second explanation of logos is the enumeration of the elementary parts of the complex whole. But this is only definition accompanied with right opinion, and does not yet attain to the certainty of knowledge. Plato does not mention the greater objection, which is, that the enumeration of particulars is endless; such a definition would be based on no principle, and would not help us at all in gaining a common idea. The third is the best explanation, – the possession of a characteristic mark, which seems to answer to the logical definition by genus and difference. But this, again, is equally necessary for right opinion; and we have already determined, although not on very satisfactory grounds, that knowledge must be distinguished from opinion. A better distinction is drawn between them in the Timaeus. They might be opposed as philosophy and rhetoric, and as conversant respectively with necessary and contingent matter. But no true idea of the nature of either of them, or of their relation to one another, could be framed until science obtained a content. The ancient philosophers in the age of Plato thought of science only as pure abstraction, and to this opinion stood in no relation.

Like Theaetetus, we have attained to no definite result. But an interesting phase of ancient philosophy has passed before us. And the negative result is not to be despised. For on certain subjects, and in certain states of knowledge, the work of negation or clearing the ground must go on, perhaps for a generation, before the new structure can begin to rise. Plato saw the necessity of combating the illogical logic of the Megarians and Eristics. For the completion of the edifice, he makes preparation in the Theaetetus, and crowns the work in the Sophist.

Many (1) fine expressions, and (2) remarks full of wisdom, (3) also germs of a metaphysic of the future, are scattered up and down in the dialogue. Such, for example, as (1) the comparison of Theaetetus' progress in learning to the 'noiseless flow of a river of oil'; the satirical touch, 'flavouring a sauce or fawning speech'; or the remarkable expression, 'full of impure dialectic'; or the lively images under which the argument is described, – 'the flood of arguments pouring in,' the fresh discussions 'bursting in like a band of revellers.' (2) As illustrations of the second head, may be cited the remark of Socrates, that 'distinctions of words, although sometimes pedantic, are also necessary'; or the fine touch in the character of the lawyer, that 'dangers came upon him when the tenderness of youth was unequal to them'; or the description of the manner in which the spirit is broken in a wicked man who listens to reproof until he becomes like a child; or the punishment of the wicked, which is not physical suffering, but the perpetual companionship of evil (compare Gorgias); or the saying, often repeated by Aristotle and others, that 'philosophy begins in wonder, for Iris is the child of Thaumas'; or the superb contempt with which the philosopher takes down the pride of wealthy landed proprietors by comparison of the whole earth. (3) Important metaphysical ideas are: a. the conception of thought, as the mind talking to herself; b. the notion of a common sense, developed further by Aristotle, and the explicit declaration, that the mind gains her conceptions of Being, sameness, number, and the like, from reflection on herself; c. the excellent distinction of Theaetetus (which Socrates, speaking with emphasis, 'leaves to grow') between seeing the forms or hearing the sounds of words in a foreign language, and understanding the meaning of them; and d. the distinction of Socrates himself between 'having' and 'possessing' knowledge, in which the answer to the whole discussion appears to be contained.

…

There is a difference between ancient and modern psychology, and we have a difficulty in explaining one in the terms of the other. To us the inward and outward sense and the inward and outward worlds of which they are the organs are parted by a wall, and appear as if they could never be confounded. The mind is endued with faculties, habits, instincts, and a personality or consciousness in which they are bound together. Over against these are placed forms, colours, external bodies coming into contact with our own body. We speak of a subject which is ourselves, of an object which is all the rest. These are separable in thought, but united in any act of sensation, reflection, or volition. As there are various degrees in which the mind may enter into or be abstracted from the operations of sense, so there are various points at which this separation or union may be supposed to occur. And within the sphere of mind the analogy of sense reappears; and we distinguish not only external objects, but objects of will and of knowledge which we contrast with them. These again are comprehended in a higher object, which reunites with the subject. A multitude of abstractions are created by the efforts of successive thinkers which become logical determinations; and they have to be arranged in order, before the scheme of thought is complete. The framework of the human intellect is not the peculium of an individual, but the joint work of many who are of all ages and countries. What we are in mind is due, not merely to our physical, but to our mental antecedents which we trace in history, and more especially in the history of philosophy. Nor can mental phenomena be truly explained either by physiology or by the observation of consciousness apart from their history. They have a growth of their own, like the growth of a flower, a tree, a human being. They may be conceived as of themselves constituting a common mind, and having a sort of personal identity in which they coexist.

So comprehensive is modern psychology, seeming to aim at constructing anew the entire world of thought. And prior to or simultaneously with this construction a negative process has to be carried on, a clearing away of useless abstractions which we have inherited from the past. Many erroneous conceptions of the mind derived from former philosophies have found their way into language, and we with difficulty disengage ourselves from them. Mere figures of speech have unconsciously influenced the minds of great thinkers. Also there are some distinctions, as, for example, that of the will and of the reason, and of the moral and intellectual faculties, which are carried further than is justified by experience. Any separation of things which we cannot see or exactly define, though it may be necessary, is a fertile source of error. The division of the mind into faculties or powers or virtues is too deeply rooted in language to be got rid of, but it gives a false impression. For if we reflect on ourselves we see that all our faculties easily pass into one another, and are bound together in a single mind or consciousness; but this mental unity is apt to be concealed from us by the distinctions of language.

A profusion of words and ideas has obscured rather than enlightened mental science. It is hard to say how many fallacies have arisen from the representation of the mind as a box, as a 'tabula rasa,' a book, a mirror, and the like. It is remarkable how Plato in the Theaetetus, after having indulged in the figure of the waxen tablet and the decoy, afterwards discards them. The mind is also represented by another class of images, as the spring of a watch, a motive power, a breath, a stream, a succession of points or moments. As Plato remarks in the Cratylus, words expressive of motion as well as of rest are employed to describe the faculties and operations of the mind; and in these there is contained another store of fallacies. Some shadow or reflection of the body seems always to adhere to our thoughts about ourselves, and mental processes are hardly distinguished in language from bodily ones. To see or perceive are used indifferently of both; the words intuition, moral sense, common sense, the mind's eye, are figures of speech transferred from one to the other. And many other words used in early poetry or in sacred writings to express the works of mind have a materialistic sound; for old mythology was allied to sense, and the distinction of matter and mind had not as yet arisen. Thus materialism receives an illusive aid from language; and both in philosophy and religion the imaginary figure or association easily takes the place of real knowledge.

Again, there is the illusion of looking into our own minds as if our thoughts or feelings were written down in a book. This is another figure of speech, which might be appropriately termed 'the fallacy of the looking-glass.' We cannot look at the mind unless we have the eye which sees, and we can only look, not into, but out of the mind at the thoughts, words, actions of ourselves and others. What we dimly recognize within us is not experience, but rather the suggestion of an experience, which we may gather, if we will, from the observation of the world. The memory has but a feeble recollection of what we were saying or doing a few weeks or a few months ago, and still less of what we were thinking or feeling. This is one among many reasons why there is so little self-knowledge among mankind; they do not carry with them the thought of what they are or have been. The so-called 'facts of consciousness' are equally evanescent; they are facts which nobody ever saw, and which can neither be defined nor described. Of the three laws of thought the first (All A = A) is an identical proposition – that is to say, a mere word or symbol claiming to be a proposition: the two others (Nothing can be A and not A, and Everything is either A or not A) are untrue, because they exclude degrees and also the mixed modes and double aspects under which truth is so often presented to us. To assert that man is man is unmeaning; to say that he is free or necessary and cannot be both is a half truth only. These are a few of the entanglements which impede the natural course of human thought. Lastly, there is the fallacy which lies still deeper, of regarding the individual mind apart from the universal, or either, as a self-existent entity apart from the ideas which are contained in them.

In ancient philosophies the analysis of the mind is still rudimentary and imperfect. It naturally began with an effort to disengage the universal from sense – this was the first lifting up of the mist. It wavered between object and subject, passing imperceptibly from one or Being to mind and thought. Appearance in the outward object was for a time indistinguishable from opinion in the subject. At length mankind spoke of knowing as well as of opining or perceiving. But when the word 'knowledge' was found how was it to be explained or defined? It was not an error, it was a step in the right direction, when Protagoras said that 'Man is the measure of all things,' and that 'All knowledge is perception.' This was the subjective which corresponded to the objective 'All is flux.' But the thoughts of men deepened, and soon they began to be aware that knowledge was neither sense, nor yet opinion – with or without explanation; nor the expression of thought, nor the enumeration of parts, nor the addition of characteristic marks. Motion and rest were equally ill adapted to express its nature, although both must in some sense be attributed to it; it might be described more truly as the mind conversing with herself; the discourse of reason; the hymn of dialectic, the science of relations, of ideas, of the so-called arts and sciences, of the one, of the good, of the all: – this is the way along which Plato is leading us in his later dialogues. In its higher signification it was the knowledge, not of men, but of gods, perfect and all sufficing: – like other ideals always passing out of sight, and nevertheless present to the mind of Aristotle as well as Plato, and the reality to which they were both tending. For Aristotle as well as Plato would in modern phraseology have been termed a mystic; and like him would have defined the higher philosophy to be 'Knowledge of being or essence,' – words to which in our own day we have a difficulty in attaching a meaning.

Yet, in spite of Plato and his followers, mankind have again and again returned to a sensational philosophy. As to some of the early thinkers, amid the fleetings of sensible objects, ideas alone seemed to be fixed, so to a later generation amid the fluctuation of philosophical opinions the only fixed points appeared to be outward objects. Any pretence of knowledge which went beyond them implied logical processes, of the correctness of which they had no assurance and which at best were only probable. The mind, tired of wandering, sought to rest on firm ground; when the idols of philosophy and language were stripped off, the perception of outward objects alone remained. The ancient Epicureans never asked whether the comparison of these with one another did not involve principles of another kind which were above and beyond them. In like manner the modern inductive philosophy forgot to enquire into the meaning of experience, and did not attempt to form a conception of outward objects apart from the mind, or of the mind apart from them. Soon objects of sense were merged in sensations and feelings, but feelings and sensations were still unanalyzed. At last we return to the doctrine attributed by Plato to Protagoras, that the mind is only a succession of momentary perceptions. At this point the modern philosophy of experience forms an alliance with ancient scepticism.

The higher truths of philosophy and religion are very far removed from sense. Admitting that, like all other knowledge, they are derived from experience, and that experience is ultimately resolvable into facts which come to us through the eye and ear, still their origin is a mere accident which has nothing to do with their true nature. They are universal and unseen; they belong to all times – past, present, and future. Any worthy notion of mind or reason includes them. The proof of them is, 1st, their comprehensiveness and consistency with one another; 2ndly, their agreement with history and experience. But sensation is of the present only, is isolated, is and is not in successive moments. It takes the passing hour as it comes, following the lead of the eye or ear instead of the command of reason. It is a faculty which man has in common with the animals, and in which he is inferior to many of them. The importance of the senses in us is that they are the apertures of the mind, doors and windows through which we take in and make our own the materials of knowledge. Regarded in any other point of view sensation is of all mental acts the most trivial and superficial. Hence the term 'sensational' is rightly used to express what is shallow in thought and feeling.

We propose in what follows, first of all, like Plato in the Theaetetus, to analyse sensation, and secondly to trace the connexion between theories of sensation and a sensational or Epicurean philosophy.

Paragraph I. We, as well as the ancients, speak of the five senses, and of a sense, or common sense, which is the abstraction of them. The term 'sense' is also used metaphorically, both in ancient and modern philosophy, to express the operations of the mind which are immediate or intuitive. Of the five senses, two – the sight and the hearing – are of a more subtle and complex nature, while two others – the smell and the taste – seem to be only more refined varieties of touch. All of them are passive, and by this are distinguished from the active faculty of speech: they receive impressions, but do not produce them, except in so far as they are objects of sense themselves.

Physiology speaks to us of the wonderful apparatus of nerves, muscles, tissues, by which the senses are enabled to fulfil their functions. It traces the connexion, though imperfectly, of the bodily organs with the operations of the mind. Of these latter, it seems rather to know the conditions than the causes. It can prove to us that without the brain we cannot think, and that without the eye we cannot see: and yet there is far more in thinking and seeing than is given by the brain and the eye. It observes the 'concomitant variations' of body and mind. Psychology, on the other hand, treats of the same subject regarded from another point of view. It speaks of the relation of the senses to one another; it shows how they meet the mind; it analyzes the transition from sense to thought. The one describes their nature as apparent to the outward eye; by the other they are regarded only as the instruments of the mind. It is in this latter point of view that we propose to consider them.

The simplest sensation involves an unconscious or nascent operation of the mind; it implies objects of sense, and objects of sense have differences of form, number, colour. But the conception of an object without us, or the power of discriminating numbers, forms, colours, is not given by the sense, but by the mind. A mere sensation does not attain to distinctness: it is a confused impression, sugkechumenon ti, as Plato says (Republic), until number introduces light and order into the confusion. At what point confusion becomes distinctness is a question of degree which cannot be precisely determined. The distant object, the undefined notion, come out into relief as we approach them or attend to them. Or we may assist the analysis by attempting to imagine the world first dawning upon the eye of the infant or of a person newly restored to sight. Yet even with them the mind as well as the eye opens or enlarges. For all three are inseparably bound together – the object would be nowhere and nothing, if not perceived by the sense, and the sense would have no power of distinguishing without the mind.

But prior to objects of sense there is a third nature in which they are contained – that is to say, space, which may be explained in various ways. It is the element which surrounds them; it is the vacuum or void which they leave or occupy when passing from one portion of space to another. It might be described in the language of ancient philosophy, as 'the Not-being' of objects. It is a negative idea which in the course of ages has become positive. It is originally derived from the contemplation of the world without us – the boundless earth or sea, the vacant heaven, and is therefore acquired chiefly through the sense of sight: to the blind the conception of space is feeble and inadequate, derived for the most part from touch or from the descriptions of others. At first it appears to be continuous; afterwards we perceive it to be capable of division by lines or points, real or imaginary. By the help of mathematics we form another idea of space, which is altogether independent of experience. Geometry teaches us that the innumerable lines and figures by which space is or may be intersected are absolutely true in all their combinations and consequences. New and unchangeable properties of space are thus developed, which are proved to us in a thousand ways by mathematical reasoning as well as by common experience. Through quantity and measure we are conducted to our simplest and purest notion of matter, which is to the cube or solid what space is to the square or surface. And all our applications of mathematics are applications of our ideas of space to matter. No wonder then that they seem to have a necessary existence to us. Being the simplest of our ideas, space is also the one of which we have the most difficulty in ridding ourselves. Neither can we set a limit to it, for wherever we fix a limit, space is springing up beyond. Neither can we conceive a smallest or indivisible portion of it; for within the smallest there is a smaller still; and even these inconceivable qualities of space, whether the infinite or the infinitesimal, may be made the subject of reasoning and have a certain truth to us.

Whether space exists in the mind or out of it, is a question which has no meaning. We should rather say that without it the mind is incapable of conceiving the body, and therefore of conceiving itself. The mind may be indeed imagined to contain the body, in the same way that Aristotle (partly following Plato) supposes God to be the outer heaven or circle of the universe. But how can the individual mind carry about the universe of space packed up within, or how can separate minds have either a universe of their own or a common universe? In such conceptions there seems to be a confusion of the individual and the universal. To say that we can only have a true idea of ourselves when we deny the reality of that by which we have any idea of ourselves is an absurdity. The earth which is our habitation and 'the starry heaven above' and we ourselves are equally an illusion, if space is only a quality or condition of our minds.

Again, we may compare the truths of space with other truths derived from experience, which seem to have a necessity to us in proportion to the frequency of their recurrence or the truth of the consequences which may be inferred from them. We are thus led to remark that the necessity in our ideas of space on which much stress has been laid, differs in a slight degree only from the necessity which appears to belong to other of our ideas, e.g. weight, motion, and the like. And there is another way in which this necessity may be explained. We have been taught it, and the truth which we were taught or which we inherited has never been contradicted in all our experience and is therefore confirmed by it. Who can resist an idea which is presented to him in a general form in every moment of his life and of which he finds no instance to the contrary? The greater part of what is sometimes regarded as the a priori intuition of space is really the conception of the various geometrical figures of which the properties have been revealed by mathematical analysis. And the certainty of these properties is immeasurably increased to us by our finding that they hold good not only in every instance, but in all the consequences which are supposed to flow from them.

Neither must we forget that our idea of space, like our other ideas, has a history. The Homeric poems contain no word for it; even the later Greek philosophy has not the Kantian notion of space, but only the definite 'place' or 'the infinite.' To Plato, in the Timaeus, it is known only as the 'nurse of generation.' When therefore we speak of the necessity of our ideas of space we must remember that this is a necessity which has grown up with the growth of the human mind, and has been made by ourselves. We can free ourselves from the perplexities which are involved in it by ascending to a time in which they did not as yet exist. And when space or time are described as 'a priori forms or intuitions added to the matter given in sensation,' we should consider that such expressions belong really to the 'pre-historic study' of philosophy, i.e. to the eighteenth century, when men sought to explain the human mind without regard to history or language or the social nature of man.

In every act of sense there is a latent perception of space, of which we only become conscious when objects are withdrawn from it. There are various ways in which we may trace the connexion between them. We may think of space as unresisting matter, and of matter as divided into objects; or of objects again as formed by abstraction into a collective notion of matter, and of matter as rarefied into space. And motion may be conceived as the union of there and not there in space, and force as the materializing or solidification of motion. Space again is the individual and universal in one; or, in other words, a perception and also a conception. So easily do what are sometimes called our simple ideas pass into one another, and differences of kind resolve themselves into differences of degree.