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.
Thomas HobbesAnd therefore in geometry (which is the only science that it hath pleased God hitherto to bestow on mankind), men begin at settling the significations of their words; which settling of significations, they call definitions, and place them in the beginning of their reckoning.
Thomas HobbesHow could a state be governed, or protected in its foreign relations if every individual remained free to obey or not to obey the law according to his private opinion.
Thomas HobbesFrom whence it happens, that they which trust to books, do as they that cast up many little sums into a greater, without considering whether those little sums were rightly cast up or not; and at last finding the error visible, and not mistrusting their first grounds, know not which way to clear themselves; but spend time in fluttering over their books, as birds that entering by the chimney, and finding themselves enclosed in a chamber, flutter at the false light of a glass window, for want of wit to consider which way they came in.
Thomas Hobbes