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itself. (3) It will be easy to discern when the evidence of the senses is doubtful, by the reflections we shall point out.' Another first truth is that a thing may be impossible although we see no contradiction in it. Again, the validity of testimony in certain cases, is a first truth; there are circumstances wherein no rational man could reject the testimony of other men. Also the free agency of man is a first truth; free will is the disposition a man feels within himself, of his capacity to act or not to act, to choose or not to choose a thing, at the same moment.'

DR. THOMAS REID. The word Sense, as used by Philosophers, from Locke to Hutcheson, has signified a means of furnishing our minds with ideas, without including judgment, which is the perception of agreement or disagreement of our ideas. But, in common language, Sense always implies judgment. Common Sense is the degree of judgment common to men that we can converse and transact business with, or call to account for their conduct. To judge of First Principles requires no more than a sound mind free from prejudice, and a distinct conception of the question. The learned and the unlearned, the philosopher and the day-labourer, are upon a level, and will pass the same judgment, when they are not misled by some bias.' A man is not now moved by the subtle arguments of Zeno against motion, though, perhaps, he knows not how to answer them.

Although First Principles are self-evident, and not to be proved by any arguments, still a certain kind of reasoning may be applied in their support. (1) To show that the principle rejected stands upon the same footing with others that are admitted. (2) As in Mathematics, the reductio ad absurdum may be employed. (3) The consent of ages and nations, of the learned and unlearned, ought to have great authority with regard to first principles, where every man is a competent judge. (4) Opinions that appear so early in the mind, that they cannot be the effect of education or of false reasoning, have a good claim to be considered as first principles.

Reid asks whether the decisions of Common Sense can be brought into a code such as all reasonable men shall acquiesce in. He acknowledges the difficulty of the task, and does not profess that his own enumeration is perfectly satisfactory. His classification proceeds on the distinction between necessary and contingent truths. That a cone is the third part of a cylinder, of the same base and height, is a necessary truth. It does not depend upon the will and power of any being. That the Sun is the centre of the planetary system is a contingent truth; it depends on the power and will of the Being that made the planets.

I.-Principles of Contingent Truth. (1) Everything that I am conscious of exists. The irresistible conviction we have of the reality of what we are conscious of, is not the effect of reasoning; it is immediate and intuitive, and therefore a first principle. (2) The thoughts that I am conscious of, are the thoughts of a being

that I call myself, my mind, my person. (3) Those things did really happen that I distinctly remember. (4) Our own personal identity and continued existence, as far back as we remember anything distinctly. (5) Those things do really exist that we distinctly perceive by our senses, and are what we perceive them to be. [This is Dr. Reid's theory of the external world elevated to the dignity of a first principle.] (6) We have some degree of power over our actions and the determinations of our will. The origin of our idea of power is not easily assigned. Power is not an object of sense or consciousness. We see events as successive, but not the power whereby they are produced. We are conscious of the operations of our minds; but power is not an operation of mind. It is, however, implied in every act of volition, and in all deliberation and resolution. Likewise, when we approve or disapprove, we believe that men have power to do or not to do. (7) The natural faculties, whereby we distinguish truth from error, are not fallacious. (8) Our fellow-men with whom we converse are possessed of life and intelligence. (9) Certain features of the countenance, sounds of the voice, and gestures of the body, indicate certain thoughts and dispositions of mind. The signification of those things we do not learn by experience, but by a kind of natural perception. Children, almost as soon as born, may be frightened by an angry or threatening tone of voice. (10) There is a certain regard due to human testimony in matters of fact, and even to human authority in matters of opinion. (11) There are many events depending on the will of man, possessing a self-evident probability, greater or less, according to circumstances. In men of sound mind, we expect a certain degree of regularity in their conduct. (12) In the phenomena of nature, what is to be, will probably be like what has been in similar circumstances. Hume has shown that this principle is not grounded on reason, and has not the intuitive evidence of mathematical axioms.

II.-Principles of Necessary Truth. In regard to those, Reid thinks it enough to divide them into classes, and to mention some by way of specimen in each class.

1. Grammatical Principles. (1) Every adjective in a sentence must belong to some substantive expressed or understood. (2) Every complete sentence must have a verb.

2. Logical Principles. (1) Any contexture of words, that does not make a proposition, is neither true nor false. (2) Every proposition is either true or false. (3) No proposition can be both true and false at the same time. (4) Reasoning in a circle proves nothing. (5) Whatever may be truly affirmed of a genus, may be truly affirmed of all its species, and of all the individuals belonging to that species.

3. The Mathematical Axioms.

4. The Principles of Taste. Setting aside the tastes acquired by habit and fashion, there is a natural taste, that is partly animal and partly rational. Rational taste is the pleasure of

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contemplating what is conceived as excellent in its kind. This taste may be true or false, according as it is founded on true or false judgment. If it may be true or false, it must have first principles. Natural taste is the pleasure or disgust arising from certain objects before we are capable of perceiving any excellence or defect in them.

5. First Principles in Morals. (1) An unjust action has more demerit than an ungenerous one. (2) A generous action has more merit than a merely just one. (3) No man ought to be blamed for what it was not in his power to hinder. (4) We ought not to do to others what we should think unjust or unfair to be done to us in like circumstances. [By endeavouring to make the golden rule more precise, Reid has converted it into an identical proposition.]

6. Metaphysical Principles. (1) The qualities that we perceive by our senses must have a subject (which we call body), and the thoughts we are conscious of must have a subject (which we call mind). The distinction between sensible qualities, and the substance to which they belong, is not the invention of philosophers, but is found in the structure of all languages. (2) Whatever begins to exist must have a cause. (3) Design and intelligence in the cause may be inferred with certainty, from marks or signs of them in the effect.

7. We may refer to some of the necessary truths regarding Matter. (1) All bodies must consist of parts. (2) Two bodies cannot occupy the same place at the same time. (3) The same body cannot be in different places at the same time. (4) A body cannot be moved from one place to another without passing through intermediate space.

We may add also some of the First Principles connected with the Senses. (1) A certain sensation of touch suggests to the mind the conception of hardness, and creates the belief of its existence. (2) The notion of extension is suggested by feelings of touch, but is not given us by any sense. (3) It is by instinct we know the part of our body affected by particular pains.

DUGALD STEWART. The chief point wherein Stewart departs from Reid in the treatment of the Fundamental Laws of Belief (as he prefers to call the dictates of Common Sense), is in regard to Mathematical demonstration.

1. Mathematical Axioms. On this subject Stewart follows Locke in preference to Reid. Locke observes that, although the axioms are appealed to in proof of particular cases, yet they are only verbal generalizations of what, in particular instances, has been already acknowledged as true. Also many of the maxims are mere verbal propositions, explaining only the meaning of words. Stewart quotes Dr. Campbell to the effect that all axioms in Arithmetic and Geometry are identical propositions-reducible to the maxim whatever is, is.' That one and four make five means that five is the name of one added to four. To this doctrine Stewart adheres so far as Arithmetic is concerned. In Algebra

and Arithmetic, All our investigations amount to nothing more, than to a comparison of different expressions of the same thing. But the axioms of Euclid are not definitions, they are universal propositions applicable to an infinite variety of instances. Reid said that the axioms are necessary truths; and so the conclusions drawn from them were necessary. But, as was observed by Locke, it is impossible to deduce from the axioms a single inference. The axioms cannot be compared with the first Principles of Natural Philosophy, such as the laws of motion, from which the subordinate truths of that science are derived. The principles of Mathematics are, not the axioms, but the definitions. Yet although nothing is deduced from the axioms, they are nevertheless implied and taken for granted in all our reasonings; without them we could not advance a step.' [In a note Stewart observes that by the Axioms he does not mean all those prefixed to Euclid, which include the definition of parallel lines. He considers it a reproach to Mathematics that the so-called Axiom regarding parallel lines has not been made the subject of demonstration.]

2. Mathematical Demonstration. Demonstrative evidence, the characteristic of mathematics, has arrested universal attention, but has not been satisfactorily explained. The true account of mathematical demonstration seems to be-that it flows from the definitions. In other sciences, the propositions we attempt to prove express facts real or supposed; in mathematics, the propositions assert merely a connexion between certain suppositions and certain consequences. The whole object is to trace the consequences flowing from an assumed hypothesis. In the same manner, we might devise arbitrary definitions about moral or political ideas, and deduce from them a science as certain as geometry. The science of mechanics is an actual instance, in which, from arbitrary hypotheses concerning physical laws, the consequences are traced which would follow, if such was really the order of nature.' In the same way, a code of law might consist of rules strictly deduced from certain principles, with much of the method and all the certainty of geometry. The reasoning of the mathematician is true only of his hypothetical circle; if applied to a figure described on paper, it would fail, because all the radii could not be proved to be exactly equal. The peculiar certainty of mathematics thus rests upon the definitions, which are hypotheses and not descriptions of facts.

Stewart considers that the certainty of arithmetic is likewise derived from hypotheses or definitions. That 22 4, and 3+25, are definitions analogous to those in Euclid, and forming the material of all the complicated results in the science. But he objects to the theory of Leibnitz, that all mathematical truths are identical propositions. The plausibility of this theory arises from the fact, that the geometrical notions of equality and of coincidence are the same; all the propositions ultimately resting upon an imaginary application of one triangle to another. As superimposed figures occupy the same space,

it

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was easy to slide into the belief that identity and equality were convertible terms. Hence it is said, all mathematical propositions are reducible to the form, a = a. But this form does not truly render the meaning of the proposition, 2 + 2:

= = 4.

3. The other Laws of Belief resemble the axioms of Geometry in two respects: 1st, they do not enlarge our knowledge; and secondly, they are implied or involved in all our reasonings. Stewart advances two objections to the phrase-principles of common sense: it designates, as principles, laws of belief from which no inference can be deduced; and secondly, it refers the origin of these laws to common sense, a phraseology that he considers unfit for the logician, and unwarranted by ordinary usage.

Stewart defends the alleged instinctive power of interpreting certain expressions of the countenance, certain gestures of the body, and certain tones of the voice. This had been resolved by Priestley into associated experiences: but, for the other opinion, Stewart offers two reasons: (1) Children understand the meaning of smiles and frowns long before they could remark the connexion between a passion and its expression. (2) We are more affected by natural signs than by artificial ones. One is more affected by the facial expression of hatred than by the word hatred.

Another instinct adduced by Stewart, is what he calls the law of Sympathetic Imitation. This is contrasted with the intentional imitation of a scholar; it depends on the mimical powers connected with our bodily frame. If we see a man laughing or sad, we have a tendency to take on the expression of those states. So yawning is contagious. 'Even when we conceive in solitude the expression of any passion, the effect of the conception is visible in our own appearance.' Also, we imitate instinctively the tones and accents of our companions. As we advance in years, this propensity to imitation grows weaker.

SIR W. HAMILTON. I.—Common Sense. All reasoning comes at last to principles that cannot be proved, but are the basis of all proof. Such primary facts rest upon consciousness. To what extent, then, is consciousness an infallible authority? What we are actually conscious of, it is impossible for scepticism to doubt; but the dicta of consciousness, as evidence of facts beyond their own existence, may without self-contradiction be disputed. Thus, the reality of our perceptions of solidity and extension is beyond controversy; but the reality of an external world, evidenced by these, may be doubted. Common Sense consists of all the original data of Consciousness.

'The argument from Common Sense is one strictly philosophical and scientific.' The decision is not refused to the judgment of philosophers and accorded to the verdict of the vulgar. The problem of philosophy, and a difficult one, is to discover the elementary feelings or beliefs. This task cannot be taken out of the hands of philosophers. Sometimes the purport of the doctrine of Common Sense has been misunderstood, and it has been