IV. Of the modern To begin with the examination of motion; 'tis eyi- SECT. dent this is a quality altogether inconceivable alone, and without a reference to some other object. The idea of motion necessarily supposes that of a body mov- philosophy. ing. Now, what is our idea of the moving body, without which motion is incomprehensible? It must resolve itself into the idea of extension or of solidity; and consequently the reality of motion depends upon that of these other qualities. This opinion, which is universally acknowledged concerning motion, I have proved to be true with regard to extension; and have shown that 'tis impossible to conceive extension but as composed of parts, endowed with colour or solidity. The idea of extension is a compound idea; but as it is not compounded of an infinite number of parts or inferior ideas, it must at last resolve itself into such as are perfectly simple and indivisible. These simple and indivisible parts not being ideas of extension, must be nonentities, unless conceived as coloured or solid. Colour is excluded from any real existence. The reality therefore of our idea of extension depends upon the reality of that of solidity; nor can the former be just while the latter is chimerical. Let us then lend our attention to the examination of the idea of solidity. The idea of solidity is that of two objects, which, being impelled by the utmost force, cannot penetrate each other, but still maintain a separate and distinct existence. Solidity therefore is perfectly incomprehensible alone, and without the conception of some bodies which are solid, and maintain this separate and distinct existence. Now, what idea have we of these bodies? The ideas of colours, sounds, and other secondary qualities, are excluded. The idea of motion IV. sceptical and PART depends on that of extension, and the idea of extension on that of solidity. 'Tis impossible, therefore, that the Of the idea of solidity can depend on either of them. For other that would be to run in a circle, and make one idea depend on another, while, at the same time, the latter depends on the former. Our modern philosophy, therefore, leaves us no just nor satisfactory idea of solidity, nor consequently of matter. systems of philosophy. This argument will appear entirely conclusive to every one that comprehends it; but because it may seem abstruse and intricate to the generality of readers, I hope to be excused if I endeavour to render it more obvious by some variation of the expression. In order to form an idea of solidity, we must conceive two bodies pressing on each other without any penetration; and 'tis impossible to arrive at this idea, when we confine ourselves to one object, much more without conceiving any. Two nonentities cannot exclude each other from their places, because they never possess any place, nor can be endowed with any quality. Now I ask, what idea do we form of these bodies or objects to which we suppose solidity to belong? To say that we conceive them merely as solid, is to run on in infinitum. To affirm that we paint them out to ourselves as extended, either resolves all into a false idea, or returns in a circle. Extension must necessarily be considered either as coloured, which is a false idea, or as solid, which brings us back to the first question. We may make the same observation concerning mobility and figure; and, upon the whole, must conclude, that after the exclusion of colours, sounds, heat and cold, from the rank of external existences, there remains nothing which can afford us a just and consistent idea of body. IV. the modern Add to this, that, properly speaking, solidity or im- SECT. penetrability is nothing but an impossibility of annihilation, as has been already observed:* for which Of reason 'tis the more necessary for us to form some dis- philosophy. tinct idea of that object whose annihilation we suppose impossible. An impossibility of being annihilated cannot exist, and can never be conceived to exist, by itself, but necessarily requires some object or real existence to which it may belong. Now, the difficulty still remains how to form an idea of this object or existence, without having recourse to the secondary and sensible qualities. Nor must we omit, on this occasion, our accustomed method of examining ideas by considering those impressions from which they are derived. The impressions which enter by the sight and hearing, the smell and taste, are affirmed by modern philosophy to be without any resembling objects; and consequently the idea of solidity, which is supposed to be real, can never be derived from any of these senses. There remains, therefore, the feeling as the only sense that can convey the impression which is original to the idea of solidity; and, indeed, we naturally imagine that we feel the solidity of bodies, and need but touch any obJect in order to perceive this quality. But this method of thinking is more popular than philosophical, as will appear from the following reflections. First, 'tis easy to observe, that though bodies are felt by means of their solidity, yet the feeling is a quite different thing from the solidity, and that they have not the least resemblance to each other. A man who has the palsy in one hand has as perfect an idea of * Part II. Sect. 4. IV. Of the sceptical and ..other PART impenetrability, when he observes that hand to be supported by the table, as when he feels the same table with the other hand. An object that presses upon any of our members meets with resistance; and philosophy, that resistance, by the motion it gives to the nerves. and animal spirits, conveys a certain sensation to the mind; but it does not follow that the sensation, motion and resistance, are any ways resembling. systems of Secondly, the impressions of touch are simple impressions, except when considered with regard to their extension; which makes nothing to the present purpose and from this simplicity I infer, that they neither represent solidity, nor any real object. For let us put two cases, viz. that of a man who presses a stone or any solid body with his hand, and that of two stones which press each other; 'twill readily be allowed that these two cases are not in every respect alike, but that in the former there is conjoined with the solidity a feeling or sensation of which there is no appearance in the latter. In order, therefore, to make these two cases alike, 'tis necessary to remove some part of the impression which the man feels by his hand, or organ of sensation; and that being impossible in a simple impression, obliges us to remove the whole, and proves that this whole impression has no archetype or model in external objects; to which we may add, that solidity necessarily supposes two bodies, along with contiguity and impulse; which being a compound object, can never be represented by a simple impression. Not to mention, that, though solidity continues always invariably the same, the impressions of touch change every moment upon us, which is a clear proof that the latter are not representations of the former. IV. Of the modern Thus there is a direct and total opposition betwixt SECT. our reason and our senses; or, more properly speaking, betwixt those conclusions we form from cause and effect, and those that persuade us of the continued philosophy. and independent existence of body. When we reason from cause and effect, we conclude, that neither colour, sound, taste nor smell, have a continued and independent existence. When we exclude these sensible qualities, there remains nothing in the universe which has such an existence, SECTION V. OF THE IMMATERIALITY OF THE SOUL. HAVING found such contradictions and difficulties in every system concerning external objects, and in the idea of matter, which we fancy so clear and determinate, we shall naturally expect still greater difficulties and contradictions in every hypothesis concerning our internal perceptions, and the nature of the mind, which we are apt to imagine so much more obscure and uncertain. But in this we should deceive ourselves. The intellectual world, though involved in infinite obscurities, is not perplexed with any such contradictions as those we have discovered in the natural. What is known concerning it, agrees with itself; and what is unknown, we must be contented to leave so. 'Tis true, would we hearken to certain philosophers, they promise to diminish our ignorance; but I am afraid 'tis at the hazard of running us into contradictions, from which the subject is of itself exempted. These philosophers are the curious reasoners concern |