Leviathan. Thomas Hobbes
such names can never be true grounds of any ratiocination. No more can Metaphors, and Tropes of speech: but these are less dangerous, because they profess their inconstancy; which the other do not.
CHAPTER V. OF REASON, AND SCIENCE.
Reason What It Is
When a man Reasoneth, hee does nothing els but conceive a summe totall, from Addition of parcels; or conceive a Remainder, from Substraction of one summe from another: which (if it be done by Words,) is conceiving of the consequence of the names of all the parts, to the name of the whole; or from the names of the whole and one part, to the name of the other part. And though in some things, (as in numbers,) besides Adding and Substracting, men name other operations, as Multiplying and Dividing; yet they are the same; for Multiplication, is but Addition together of things equall; and Division, but Substracting of one thing, as often as we can. These operations are not incident to Numbers onely, but to all manner of things that can be added together, and taken one out of another. For as Arithmeticians teach to adde and substract in Numbers; so the Geometricians teach the same in Lines, Figures (solid and superficiall,) Angles, Proportions, Times, degrees of Swiftnesse, Force, Power, and the like; The Logicians teach the same in Consequences Of Words; adding together Two Names, to make an Affirmation; and Two Affirmations, to make a syllogisme; and Many syllogismes to make a Demonstration; and from the Summe, or Conclusion of a syllogisme, they substract one Proposition, to finde the other. Writers of Politiques, adde together Pactions, to find mens Duties; and Lawyers, Lawes and Facts, to find what is Right and Wrong in the actions of private men. In summe, in what matter soever there is place for Addition and Substraction, there also is place for Reason; and where these have no place, there Reason has nothing at all to do.
Reason Defined
Out of all which we may define, (that is to say determine,) what that is, which is meant by this word Reason, when wee reckon it amongst the Faculties of the mind. For Reason, in this sense, is nothing but Reckoning (that is, Adding and Substracting) of the Consequences of generall names agreed upon, for the Marking and Signifying of our thoughts; I say Marking them, when we reckon by our selves; and Signifying, when we demonstrate, or approve our reckonings to other men.
Right Reason Where
And as in Arithmetique, unpractised men must, and Professors themselves may often erre, and cast up false; so also in any other subject of Reasoning, the ablest, most attentive, and most practised men, may deceive themselves, and inferre false Conclusions; Not but that Reason it selfe is always Right Reason, as well as Arithmetique is a certain and infallible art: But no one mans Reason, nor the Reason of any one number of men, makes the certaintie; no more than an account is therefore well cast up, because a great many men have unanimously approved it. And therfore, as when there is a controversy in an account, the parties must by their own accord, set up for right Reason, the Reason of some Arbitrator, or Judge, to whose sentence they will both stand, or their controversie must either come to blowes, or be undecided, for want of a right Reason constituted by Nature; so is it also in all debates of what kind soever: And when men that think themselves wiser than all others, clamor and demand right Reason for judge; yet seek no more, but that things should be determined, by no other mens reason but their own, it is as intolerable in the society of men, as it is in play after trump is turned, to use for trump on every occasion, that suite whereof they have most in their hand. For they do nothing els, that will have every of their passions, as it comes to bear sway in them, to be taken for right Reason, and that in their own controversies: bewraying their want of right Reason, by the claym they lay to it.
The Use Of Reason
The Use and End of Reason, is not the finding of the summe, and truth of one, or a few consequences, remote from the first definitions, and settled significations of names; but to begin at these; and proceed from one consequence to another. For there can be no certainty of the last Conclusion, without a certainty of all those Affirmations and Negations, on which it was grounded, and inferred. As when a master of a family, in taking an account, casteth up the summs of all the bills of expence, into one sum; and not regarding how each bill is summed up, by those that give them in account; nor what it is he payes for; he advantages himselfe no more, than if he allowed the account in grosse, trusting to every of the accountants skill and honesty; so also in Reasoning of all other things, he that takes up conclusions on the trust of Authors, and doth not fetch them from the first Items in every Reckoning, (which are the significations of names settled by definitions), loses his labour; and does not know any thing; but onely beleeveth.
Of Error And Absurdity
When a man reckons without the use of words, which may be done in particular things, (as when upon the sight of any one thing, wee conjecture what was likely to have preceded, or is likely to follow upon it;) if that which he thought likely to follow, followes not; or that which he thought likely to have preceded it, hath not preceded it, this is called ERROR; to which even the most prudent men are subject. But when we Reason in Words of generall signification, and fall upon a generall inference which is false; though it be commonly called Error, it is indeed an ABSURDITY, or senseless Speech. For Error is but a deception, in presuming that somewhat is past, or to come; of which, though it were not past, or not to come; yet there was no impossibility discoverable. But when we make a generall assertion, unlesse it be a true one, the possibility of it is unconceivable. And words whereby we conceive nothing but the sound, are those we call Absurd, insignificant, and Non-sense. And therefore if a man should talk to me of a Round Quadrangle; or Accidents Of Bread In Cheese; or Immaterial Substances; or of A Free Subject; A Free Will; or any Free, but free from being hindred by opposition, I should not say he were in an Errour; but that his words were without meaning; that is to say, Absurd.
I have said before, (in the second chapter,) that a Man did excell all other Animals in this faculty, that when he conceived any thing whatsoever, he was apt to enquire the consequences of it, and what effects he could do with it. And now I adde this other degree of the same excellence, that he can by words reduce the consequences he findes to generall Rules, called Theoremes, or Aphorismes; that is, he can Reason, or reckon, not onely in number; but in all other things, whereof one may be added unto, or substracted from another.
But this priviledge, is allayed by another; and that is, by the priviledge of Absurdity; to which no living creature is subject, but man onely. And of men, those are of all most subject to it, that professe Philosophy. For it is most true that Cicero sayth of them somewhere; that there can be nothing so absurd, but may be found in the books of Philosophers. And the reason is manifest. For there is not one of them that begins his ratiocination from the Definitions, or Explications of the names they are to use; which is a method that hath been used onely in Geometry; whose Conclusions have thereby been made indisputable.
Causes Of Absurditie
The first cause of Absurd conclusions I ascribe to the want of Method; in that they begin not their Ratiocination from Definitions; that is, from settled significations of their words: as if they could cast account, without knowing the value of the numerall words, One, Two, and Three.
And whereas all bodies enter into account upon divers considerations, (which I have mentioned in the precedent chapter;) these considerations being diversly named, divers absurdities proceed