A modern philosopher, though emancipated from scholastic notions of essence or substance, might still be seriously affected by the abstract idea of necessity; or though accustomed, like Bacon, to criticize abstract notions, might not extend his criticism to the syllogism.
The saying or thinking the thing that is not, would be the popular definition of falsehood or error. If we were met by the Sophist's objection, the reply would probably be an appeal to experience. Ten thousands, as Homer would say (mala murioi), tell falsehoods and fall into errors. And this is Plato's reply, both in the Cratylus and Sophist. 'Theaetetus is flying,' is a sentence in form quite as grammatical as 'Theaetetus is sitting'; the difference between the two sentences is, that the one is true and the other false. But, before making this appeal to common sense, Plato propounds for our consideration a theory of the nature of the negative.
The theory is, that Not-being is relation. Not-being is the other of Being, and has as many kinds as there are differences in Being. This doctrine is the simple converse of the famous proposition of Spinoza, – not 'Omnis determinatio est negatio,' but 'Omnis negatio est determinatio'; – not, All distinction is negation, but, All negation is distinction. Not-being is the unfolding or determining of Being, and is a necessary element in all other things that are. We should be careful to observe, first, that Plato does not identify Being with Not-being; he has no idea of progression by antagonism, or of the Hegelian vibration of moments: he would not have said with Heracleitus, 'All things are and are not, and become and become not.' Secondly, he has lost sight altogether of the other sense of Not-being, as the negative of Being; although he again and again recognizes the validity of the law of contradiction. Thirdly, he seems to confuse falsehood with negation. Nor is he quite consistent in regarding Not-being as one class of Being, and yet as coextensive with Being in general. Before analyzing further the topics thus suggested, we will endeavour to trace the manner in which Plato arrived at his conception of Not-being.
In all the later dialogues of Plato, the idea of mind or intelligence becomes more and more prominent. That idea which Anaxagoras employed inconsistently in the construction of the world, Plato, in the Philebus, the Sophist, and the Laws, extends to all things, attributing to Providence a care, infinitesimal as well as infinite, of all creation. The divine mind is the leading religious thought of the later works of Plato. The human mind is a sort of reflection of this, having ideas of Being, Sameness, and the like. At times they seem to be parted by a great gulf (Parmenides); at other times they have a common nature, and the light of a common intelligence.
But this ever-growing idea of mind is really irreconcilable with the abstract Pantheism of the Eleatics. To the passionate language of Parmenides, Plato replies in a strain equally passionate: – What! has not Being mind? and is not Being capable of being known? and, if this is admitted, then capable of being affected or acted upon? – in motion, then, and yet not wholly incapable of rest. Already we have been compelled to attribute opposite determinations to Being. And the answer to the difficulty about Being may be equally the answer to the difficulty about Not-being.
The answer is, that in these and all other determinations of any notion we are attributing to it 'Not-being.' We went in search of Not-being and seemed to lose Being, and now in the hunt after Being we recover both. Not-being is a kind of Being, and in a sense co-extensive with Being. And there are as many divisions of Not-being as of Being. To every positive idea – 'just,' 'beautiful,' and the like, there is a corresponding negative idea – 'not-just,' 'not-beautiful,' and the like.
A doubt may be raised whether this account of the negative is really the true one. The common logicians would say that the 'not-just,' 'not-beautiful,' are not really classes at all, but are merged in one great class of the infinite or negative. The conception of Plato, in the days before logic, seems to be more correct than this. For the word 'not' does not altogether annihilate the positive meaning of the word 'just': at least, it does not prevent our looking for the 'not-just' in or about the same class in which we might expect to find the 'just.' 'Not-just is not-honourable' is neither a false nor an unmeaning proposition. The reason is that the negative proposition has really passed into an undefined positive. To say that 'not-just' has no more meaning than 'not-honourable' – that is to say, that the two cannot in any degree be distinguished, is clearly repugnant to the common use of language.
The ordinary logic is also jealous of the explanation of negation as relation, because seeming to take away the principle of contradiction. Plato, as far as we know, is the first philosopher who distinctly enunciated this principle; and though we need not suppose him to have been always consistent with himself, there is no real inconsistency between his explanation of the negative and the principle of contradiction. Neither the Platonic notion of the negative as the principle of difference, nor the Hegelian identity of Being and Not-being, at all touch the principle of contradiction. For what is asserted about Being and Not-Being only relates to our most abstract notions, and in no way interferes with the principle of contradiction employed in the concrete. Because Not-being is identified with Other, or Being with Not-being, this does not make the proposition 'Some have not eaten' any the less a contradiction of 'All have eaten.'
The explanation of the negative given by Plato in the Sophist is a true but partial one; for the word 'not,' besides the meaning of 'other,' may also imply 'opposition.' And difference or opposition may be either total or partial: the not-beautiful may be other than the beautiful, or in no relation to the beautiful, or a specific class in various degrees opposed to the beautiful. And the negative may be a negation of fact or of thought (ou and me). Lastly, there are certain ideas, such as 'beginning,' 'becoming,' 'the finite,' 'the abstract,' in which the negative cannot be separated from the positive, and 'Being' and 'Not-being' are inextricably blended.
Plato restricts the conception of Not-being to difference. Man is a rational animal, and is not – as many other things as are not included under this definition. He is and is not, and is because he is not. Besides the positive class to which he belongs, there are endless negative classes to which he may be referred. This is certainly intelligible, but useless. To refer a subject to a negative class is unmeaning, unless the 'not' is a mere modification of the positive, as in the example of 'not honourable' and 'dishonourable'; or unless the class is characterized by the absence rather than the presence of a particular quality.
Nor is it easy to see how Not-being any more than Sameness or Otherness is one of the classes of Being. They are aspects rather than classes of Being. Not-being can only be included in Being, as the denial of some particular class of Being. If we attempt to pursue such airy phantoms at all, the Hegelian identity of Being and Not-being is a more apt and intelligible expression of the same mental phenomenon. For Plato has not distinguished between the Being which is prior to Not-being, and the Being which is the negation of Not-being (compare Parm.).
But he is not thinking of this when he says that Being comprehends Not-being. Again, we should probably go back for the true explanation to the influence which the Eleatic philosophy exercised over him. Under 'Not-being' the Eleatic had included all the realities of the sensible world. Led by this association and by the common use of language, which has been already noticed, we cannot be much surprised that Plato should have made classes of Not-being. It is observable that he does not absolutely deny that there is an opposite of Being. He is inclined to leave the question, merely remarking that the opposition, if admissible at all, is not expressed by the term 'Not-being.'
On the whole, we must allow that the great service rendered by Plato to metaphysics in the Sophist, is not his explanation of 'Not-being' as difference. With this he certainly laid the ghost of 'Not-being'; and we may attribute to him in a measure the credit of anticipating Spinoza and Hegel. But his conception is not clear or consistent; he does not recognize the different senses of the negative, and he confuses the different classes of Not-being with the abstract notion. As the Pre-Socratic philosopher failed to distinguish between the universal and the true, while he placed the particulars of sense under the false and apparent, so Plato appears to identify negation with falsehood, or is unable to distinguish them. The greatest service rendered by him to mental science is the recognition of the communion of classes, which, although based by him on his account
