ties and these have by fome been reduced to two; Reafon and Judgement; the former being fuppofed to be converfant about certain truths, the latter chiefly about probabilities. But certain truths are not all of the fame kind; fome being fupported by one fort of evidence, and others by another: different energies of the understanding must therefore be exerted in perceiving them; and these different energies must be expreffed by different names, if we would fpeak of them dif tinctly and intelligibly. The certainty of fome truths, for inftance, is perceived intuitively; the certainty of others is perceived not intuitively, but in confequence of a proof. Most of the propofitions of Euclid are of the latter kind; the axioms of geometry arc of the former. Now, if that faculty by which we perceive truth in confequence of a proof, be called Reafon, that power by which we perceive felf-evident truth, ought to be distinguished by a different name. It is of little confequence what name we make choice of, provided that in chufing it we depart not from the analogy of language; and that, in applying it, we avoid equivocation and ambiguity. Some philofophers of note † have given the name of Common Senfe We might call the one Reafon and the other Reafoning; but the fimilarity of the terms would frequently occafion both obfcurity in the fenfe, and harshness in the found. + Dr Reid, &c. to 1 I to that faculty by which we perceive felfevident truth; and, as the term seems proper enough, we shall adopt it. But in a fubject of this kind, there is great danger of our being impofed upon by words; we cannot therefore be too much upon our guard against that fpecies of illufion. We mean to draw fome important inferences from this doctrine of the diftinction between Reason and Common Senfe. Now thefe words are not always used in the strict fignification we have here affigned them: let us therefore take a view of all the fimilar fenfes in which they are commonly used, and let us explain more particularly that sense in which we are to use them; and thus we shall take every method in our power to fecure ourselves against the impropriety of confounding our notions by the ufe of ambiguous and indefinite language. Thefe philological difcuffions are indeed no part of philofophy; but they are very neceffary to prepare us for it, "Qui ad interpretandum naturam accefferit," fays Bacon, "verborum mixtam na turam, et juvamenti et nocumenti impri"mis participem, diftincte fciat." This diftinction between Common Senfe and Reason is no modern difcovery †. The ancient De interpretatione Naturæ, fent. 9. + The norovonμoourn of the Greck Stoics feems to mean that benevolent affection which men owe to fociety and to ancient geometricians were all acquainted with it. Ariftotle treats of felf-evident principles in many parts of his works, particularly in the fourth book of his Metaphyfics, and in the first book of his latter Analytics. He calls them, Axioms or Dignities, Principles, and Common Sentiments *; and fays of them, "That they are known by their own to one another. Some modern moralifts have called it the Public Senfe. But the notion or idea we mean to exprefs by the term Common Senfe is quite different. The Senfus Communis of the Latins hath feveral fignifications. 1. It denotes this Public Senfe, or nowovonposuvn. See Shaftesbury's Effay on the freedom of wit and humour, part 3. fect. 1. Note. 2. It denotes that experience and knowledge of life which is acquired by living in fociety. Thus Horace feems to use it, lib. 1. fatir. 3. lin 66. And thus Quintilian, fpeaking of the advantages of a public education: "Senfum ipfum qui communis dicitur, "ubi difcet, cum fe a congreffu, qui non hominibus folum, "fed mutis quoque animalibus naturalis eft, fegregarit;" lib. 1. cap. 2. 3. It feems to fignify that inftinctive per fuafion of truth which arifes from intuitive evidence, and is the foundation of all reafoning: "Corpus enim per fe communis deliquat effe * Αξιώματα, Αρχαι, τίκας, και τας κοινας δόξας, Lucretius, lib. 1. ver. 423. Κοιναι δόξαι. — Λέγω δε ἀποδεικ ἐξ ὧν ἀπαντες δεικνύασι· οἷον, ὅτι πᾶν αναγκαῖον ἢ φαγαι, ἢ ἀποφάναι. καὶ ἀδυνατον ἅμα είναι κ μὴ εἶναι. Metaphyf. lib. 3. cap. 2. "evidence " evidence *; that except fome first prin ciples be taken for granted, there can be "neither reafon nor reafoning; that it is "impoffible that every truth fhould admit "of proof, otherwise proof would extend in "infinitum, which is incompatible with its 66 * Analytic, lib. 2. cap. 16. Of these first principles, a French Peripatetic, who wrote about the beginning of the last century, expreffes himself thus: "Ces "principes portent le nom de communs, non feulement parce qu'ils fervent à plufieurs fciences, mais auffi parce que l'intelligence en eft commune à tous. On les appelle "auffi dignitez, et notions communes : à fçavoir, dignitez, "quafi comme dignes entre toutes les autres qu'on y "adioufte foy, à caufe de la grande excellence de leur "clarté et evidence; et notions communes, pour ce "qu'ils font fi connus, qu' auffi toft que la fignification. "des termes dont ils font compofez eft entendue, fans "difcourir ny argumenter davantage deffus, chacun en"tend naturellement leur verité; fi ce n'eft quelque he"beté privé de raifon; lequel je revoye à Ariftote, qui pronounce, que ceux qui doutent, qu'il faut reverer "les Dieux, ou aymer les parents, meritent d'eftre pu"nis; et que ceux qui doutent que la nege eft blanche "ont befoin de fens: et à Averroes, qui dit, que ceux "qui ne fçauroient diftinguer ce qui eft connu par foy "d'avec ce qui ne l'eft pas, font incapables de philofo"pher; et que ne pouvoir connoiftre ces principes, procede de quelque defaut de nature, ou de peu "d'exercice, ou d'une mauvaife accouftumance enra"cinée." Corps de toute la Philofophie de Theophrafte Bouju, p. 79. * Μηδεν γαρ τιθέντες, ἀναιρέσι το διαλέγεσθαι, καὶ ὅλως λόγον. Ariftot. Metaphyf. lib. 2. cap. 6. nature * ; nature and that if ever men attempt to prove a first principle, it is because they ἐσ are ignorant of the nature of proof +." The word Reafon is ufed in feveral different fenfes. 1. It is ufed to fignify that quality of human nature which distinguishes man from the inferior animals. Man is called a reasonable being, and the brutes are faid to be irrational. But the faculty of reafon, taking the word in a ftrict fenfe, is perhaps not more characteristical of the nature of man, than his moral faculty, or his imagination, or his power of artificial language, or his rifibility. Reafon, in this acceptation, feems to be a general name for all the intellectual powers, as diftinguished from the fenfitive part of our conftitution. 2. Every thing that is called truth is faid to be perceived by reafon: by reafon, we are faid to perceive, that the three angles of a triangle are equal to two right angles; and we are alfo faid to perceive, by reafon, that it is im * Όλως μεν γαρ ἁπάντων ἀδύνατον ἀπόδειξιν είναι εις άπειρον γαρ αν βαδίζοι· ώςε μηδ' όντως είναι ἀποδειξιν. Ariftot. Metyphyf. lib. 4. cap. 4. + Αξίουσι δε καὶ τᾶτο ἀποδεικνύναι τινες δὲ ἀπαιδευσίαν· ἐστὶ γαρ απαιδευσία, το μη γινωσκειν τίνων δεν ζητῶν ἀποδειξιν, τινων οὐ δεῖ. Arift. Metaphyf. lib. 4. cap. 4. I cite these authorities, that I may not be fuppofed to affect either an uncommon doctrine, or uncommon modes of expreflion. 2 poffible |