In sum, in what matter soever there is place for _addition_ and _subtraction_, there also is place for _reason_; and where these have no place, there _reason_ has nothing at all to do. [Sidenote: 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 we reckon it amongst the faculties of the mind. For REASON, in this sense, is nothing but _reckoning_, that is adding and subtracting, of the consequences of general names agreed upon for the _marking_ and _signifying_ of our thoughts; I say _marking_ them when we reckon by ourselves, and _signifying_, when we demonstrate or approve our reckonings to other men. [Sidenote: Right reason, where.] And, as in arithmetic, unpractised men must, and professors themselves may often, err, and cast up false; so also in any other subject of reasoning, the ablest, most attentive, and most practised men may deceive themselves, and infer false conclusions; not but that reason itself is always right reason, as well as arithmetic is a certain and infallible art: but no one man’s reason, nor the reason of any one number of men, makes the certainty; no more than an account is therefore well cast up, because a great many men have unanimously approved it. And therefore, 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 controversy must either come to blows, 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, clamour and demand right reason for judge, yet seek no more, but that things should be determined, by no other men’s 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 else, 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 claim they lay to it. [Sidenote: The use of reason.]