8. And from hence it is evident, that truth and falsity have no place but amongst such living creatures as use speech. For though some brute creatures, looking upon the image of a man in a glass, may be affected with it, as if it were the man himself, and for this reason fear it or fawn upon it in vain; yet they do not apprehend it as true or false, but only as like; and in this they are not deceived. Wherefore, as men owe all their true ratiocination to the right understanding of speech; so also they owe their errors to the misunderstanding of the same; and as all the ornaments of philosophy proceed only from man, so from man also is derived the ugly absurdity of false opinions. For speech has something in it like to a spider's web, (as it was said of old of _Solon's_ laws) for by contexture of words tender and delicate wits are ensnared and stopped; but strong wits break easily through them. From hence also this may be deduced, that the first truths were arbitrarily made by those that first of all imposed names upon things, or received them from the imposition of others. For it is true (for example) that _man is a living creature_, but it is for this reason, that it pleased men to impose both those names on the same thing. [Sidenote: Proposition, primary, not primary, definition, axiom, petition.] 9. Fourthly, propositions are distinguished into _primary_ and _not primary_. _Primary_ is that wherein the subject is explicated by a predicate of many names, as _man is a body_, _animated_, _rational_; for that which is comprehended in the name _man_, is more largely expressed in the names _body_, _animated_, and _rational_, joined together; and it is called _primary_, because it is first in ratiocination; for nothing can be proved, without understanding first the name of the thing in question. Now _primary_ propositions are nothing but definitions, or parts of definitions, and these only are the principles of demonstration, being truths constituted arbitrarily by the inventors of speech, and therefore not to be demonstrated. To these propositions, some have added others, which they call _primary_ and _principles_, namely, _axioms_, and _common notions_; which, (though they be so evident that they need no proof) yet, because they may be proved, are not truly principles; and the less to be received for such, in regard propositions not intelligible, and sometimes manifestly false, are thrust on us under the name of _principles_ by the clamour of men, who obtrude for evident to others, all that they themselves think true. Also certain petitions are commonly received into the number of principles; as, for example, _that a straight line may be drawn between two points_, and other petitions of the writers of geometry; and these are indeed the principles of art or construction, but not of science and demonstration. [Sidenote: Proposition necessary & contingent.]