------- CHAPTER II. 2. Definition of sense. 4. Four propositions concerning the nature of conceptions. 5. The first proved. 6. The second proved. 7, 8. The third proved. 9. The fourth proved. 10. The main deception of sense. 1. Having declared what I mean by the word _conception_, and other words equivalent thereunto, I come to the _conceptions_ themselves, to shew their _differences_, their _causes_, and the _manner of the production_, so far as is necessary for this place. [Sidenote: Definition of sense.] 2. Originally all _conceptions_ proceed from the _action_ of the thing itself, whereof it is the conception: now when the action is _present_, the conception it produceth is also called _sense_; and the thing by whose action the same is produced, is called the _object of the sense_. 3. By our several _organs_ we have several _conceptions_ of several qualities in the objects; for by _sight_ we have a conception or image composed of _colour_ and _figure_, which is all the notice and knowledge the object imparteth to us of its nature by the eye. By _hearing_ we have a conception called _sound_, which is all the knowledge we have of the quality of the object from the ear. And so the rest of the senses are also conceptions of several qualities, or natures of their objects. [Sidenote: Four propositions concerning the nature of conceptions.] 4. Because the _image_ in vision consisting of _colour_ and _shape_ is the knowledge we have of the qualities of the object of that sense; it is no hard matter for a man to fall into this opinion, that the same _colour_ and _shape_ are the _very qualities themselves_; and for the same cause, that _sound_ and _noise_ are the _qualities of the bell_, or of the air. And this opinion hath been so long received, that the _contrary_ must needs appear a great paradox; and yet the introduction of _species visible_ and _intelligible_ (which is necessary for the maintenance of that opinion) passing to and fro from the _object_, is _worse_ than any paradox, as being a plain _impossibility_. I shall therefore endeavour to make plain these points: That the subject wherein colour and image are inherent, is _not_ the _object_ or thing seen. That there is nothing _without us_ (really) which we call an _image_ or colour. That the said image or colour is but an _apparition_ unto us of the _motion_, agitation, or alteration, which the _object_ worketh in the _brain_, or spirits, or some internal substance of the head. That as in _vision_, so also in conceptions that arise from the _other senses_, the subject of their _inherence_ is not the _object_, but the _sentient_. [Sidenote: The first proved]