Of simple Ideas
§ 1. THE better to understand the Nature, Manner, and Extent of our Knowledge, one thing is carefully to be observed, concerning the Ideas we have; and that is, That some of them are simple, and some complex.
Though the Qualities that affect our Senses, are, in the things themselves, so united and blended, that there is no separation, no distance between them; yet ’tis plain, the Ideas they produce in the Mind, enter by the Senses simple and unmixed. For though the Sight and Touch often take in from the [108]same Object, at the same time, different Ideas; as a Man sees at once Motion and Colour; the Hand feels Softness and Warmth in the same piece of Wax: Yet the simple Ideas thus united in the same Subject, are as perfectly distinct, as those that come in by different Senses. The coldness and hardness, which a Man feels in a piece of Ice, being as distinct Ideas in the Mind, as the Smell and Whiteness of a Lily; or as the taste of Sugar, and smell of a Rose: And there is nothing can be plainer to a Man, than the clear and distinct Perception he has of those simple Ideas; which being each in it self uncompounded, contains in it nothing but one uniform Appearance, or Conception in the mind, and is not distinguishable into different Ideas.
§ 2. These simple Ideas, the Materials of all our Knowledge, are suggested and furnished to the Mind, only by those two ways above mentioned, viz. Sensation and Reflection. When the Understanding is once stored with these simple Ideas, it has the Power to repeat, compare, and unite them even to an almost infinite Variety, and so can make at Pleasure new complex Ideas. But it is not in the Power of the most exalted Wit, or enlarged Understanding, by any quickness or variety of Thought, to invent or frame one new simple Idea in the mind, not taken in by the ways before mentioned: nor can any force of the Understanding, destroy those that are there. […]
§ 3. This is the Reason why, though we cannot believe it impossible to God, to make a Creature with other Organs, and more ways to convey into the Understanding the notice of Corporeal things, than those five, as they are usually counted, which he has given to Man: Yet I think, it is not possible, for any [110]one to imagine any other Qualities in Bodies, howsoever constituted, whereby they can be taken notice of, besides Sounds, Tastes, Smells, visible and tangible Qualities. And had Mankind been made with but four Senses, the Qualities then, which are the Object of the Fifth Sense, had been as far from our Notice, Imagination, and Conception, as now any belonging to a sixth, seventh, or eighth Sense, can possibly be: which, whether yet some other Creatures, in some other Parts of this vast, and stupendious Universe, may not have, will be a great Presumption to deny. […]
Of Ideas of one Sense
§ 1. THE better to conceive the Ideas, we receive from Sensation, it may not be amiss for us to consider them, in reference to the different ways, whereby they make their Approaches to our minds, and make themselves perceivable by us.
First then, There are some, which come into our minds by one Sense only.
Secondly, There are others, that convey themselves into the mind by more Senses than one.
Thirdly, Others that are had from Reflection only.
Fourthly, There are some that make themselves way, and are suggested to the mind by all the ways of Sensation and Reflection.
We shall consider them apart under these several Heads.
[112]First, There are some Ideas, which have admittance only through one Sense, which is peculiarly adapted to receive them. Thus Light and Colours, as white, red, yellow, blue; with their several Degrees or Shades, and Mixtures, as Green, Scarlet, Purple, Sea-green, and the rest, come in only by the Eyes: All kinds of Noises, Sounds, and Tones, only by the Ears: The several Tastes and Smells, by the Nose and Palate. And if these Organs, or the Nerves which are the Conduits, to convey them from without to their Audience in the Brain, the mind’s Presence-room (as I may so call it) are any of them so disordered, as not to perform their Functions, they have no Postern to be admitted by; no other way to bring themselves into view, and be perceived by the Understanding.
The most considerable of those, belonging to the Touch, are Heat and Cold, and Solidity; all the rest, consisting almost wholly in the sensible Configuration, as smooth and rough; or else more, or less firm adhesion of the Parts, as hard and soft, tough and brittle, are obvious enough.
§ 2. I think, it will be needless to enumerate all the particular simple Ideas, belonging to each Sense. Nor indeed is it possible, if we would, there being a great many more of them belonging to most of the Senses, than we have Names for. […] I shall therefore in the account of simple Ideas, I am here giving, content my self to set down only such, as are most material to our present Purpose, or are in themselves less apt to be taken notice of, though they are very frequently the Ingredients of our complex Ideas, amongst which, I think, I may well account Solidity; which therefore I shall treat of in the next Chapter.
Of Solidity
§ 1. THE Idea of Solidity we receive by our Touch; and it arises from the resistance which we find in Body, to the entrance of any other Body into the Place it possesses, till it has left it. There is no Idea, which we receive more constantly from Sensation, than Solidity. Whether we move, or rest, in what Posture soever we are, we always feel something under us, that supports us, and hinders our farther sinking downwards; and the Bodies which we daily handle, make us perceive, that, whilst they remain between them, they do by an insurmountable Force, hinder the approach of the parts of our Hands that press them. That which thus hinders the approach of two Bodies, when they are moving one towards another, I call Solidity. I will not dispute, whether this acceptation of the Word solid be nearer to its Original Signification, than that which Mathematicians use it in: It suffices, that I think, the common Notion of Solidity will allow, if not justifie, this use of it; but if any one think it better to call it Impenetrability, he has my Consent. Only I have thought the Term Solidity, the more proper to express this Idea, not only because of its vulgar use in that Sense; but also, because it carries something more of positive in it, than Impenetrability, which is negative, and is, perhaps, more a consequence of Solidity, than Solidity it self. This of all other, seems the Idea most intimately connected with, and essential to Body, so as no where else to be found or imagin’d, but only [116]in matter: and though our Senses take no notice of it, but in masses of matter, of a bulk sufficient to cause a Sensation in us; Yet the Mind, having once got this Idea from such grosser sensible Bodies, traces it farther; and considers it, as well as Figure, in the minutest Particle of Matter, that can exist; and finds it inseparably inherent in Body, where-ever or however modified.
§ 2. This is the Idea belongs to Body, whereby we conceive it to fill space. The Idea of which filling of space, is, That where we imagine any space taken up by a solid Substance, we conceive it so to possess it, that it excludes all other solid Substances; and, will for ever hinder any two other Bodies, that move towards one another in a strait Line, from coming to touch one another, unless it removes from between them in a Line, not parallel to that which they move in. This Idea of it the Bodies, which we ordinarily handle, sufficiently furnish us with.
§ 3. This Resistance, whereby it keeps other Bodies out of the space which it possesses, is so great, That no force, how great soever, can surmount it. All the Bodies in the World, pressing a drop of Water on all sides, will never be able to overcome the Resistance which it will make, as soft as it is, to their approaching one another, till it be removed