historians upon contested facts. When an individual fact is doubted upon reasonable grounds, its existence becomes a matter of opinion. The existence of such a fact, however, is not a general or scientific truth, but a question to be decided by a consideration of the testimony of witnesses.

Matters of Opinion, not being disputed questions of fact, are general propositions or theorems relating to laws of nature or mind, principles and rules of human conduct, future probabilities, deductions from hypotheses, and the like, about which a doubt may reasonably exist. All doubtful questions, whether of speculation or practice, are matters of opinion. With regard to these, the ultimate source of our belief is always a process of reasoning.*

The proper mode of conducting this process, of guarding against errors of induction and deduction, of testing the soundness of existing arguments, and of establishing new truths by ratiocination; is the province

* "I remember it was with extreme difficulty that I could bring my master to understand the meaning of the word opinion, or how a point could be disputable; because reason taught us to affirm or deny only where we are certain, and beyond our knowledge we cannot do either. So that controversies, wranglings, disputes, and positiveness in false or dubious propositions, are evils unknown among the Houyhnhnms."-SWIFT.

The essential idea of opinion seems to be that it is a matter about which doubt can reasonably exist, as to which two persons can without absurdity think differently. The existence of an object before the eyes of two persons would not be a matter of opinion, nor would it be a matter of opinion that twice two are four. But when testimony is divided, or uncertain, the existence of a fact may become doubtful, and, therefore, a matter of opinion. For example, it may be a matter of opinion whether there was a war of Troy, whether Romulus lived, who was the man in the iron mask, who

of logical science. The science of logic, having been created by the inventive and penetrating genius of Aristotle, and afterwards systematized by the Schoolmen, was enlarged by the sagacious divinations of Bacon, who indicated its applications to natural philosophy, and freed it from much of the needless subtlety of the schools. Since the publication of the Novum Organon, the fundamental processes of thought connected with reasoning have been explored by Locke, Leibnitz, and the metaphysicians who have followed in their steps: and of late years, logical science has, in this country, received much illustration and improvement, from the writings of Archbishop Whately, Dr. Whewell, and Mr. John Mill: of whom, the first has improved the form of the scholastic logic, and adapted it to the wants of modern students; the second has expounded the philosophy of induction, and of its subsidiary processes, as applied to the whole field of the physical sciences; while the latter has determined the province of logic with precision, has established its first principles on a sound

wrote Junius, &c. So the tendency of a law or form of government, or social institution, the probability of a future event, the quality of an action or the character of an historical personage, may be a matter of opinion.

Any proposition, the contradictory of which can be maintained with probability, is a matter of opinion.

The distinction between matters of fact and matters of opinion is recognized by Bacon, Advancement of Learning, vol. ii. p. 42, ed. Montagu. See also Locke, Essay on the Understanding, B. IV. c. xvi. § 5; On the Conduct of the Understanding, § 24; and Whately, Rhetoric, Part. I. c. iii. § 3.

In the language of jurists, questions of fact are opposed to questions of law. Hence the maxim of our law: "De jure respondent judices, de facto jurati." On this subject, see Bentham On Judicial Evidence by Dumont, B. I. c. v.

basis, and has systematized the methods of observation and deduction, for all the subjects of scientific research.

Upon the field of logical science, as defined by the writers whom I have referred to, I do not propose to encroach. The object of the following pages will be of a subordinate and more limited kind. Without entering into any inquiry into the process of reasoning, or attempting to throw any light upon scientific method, it will concern a portion of the application of logical science, which has often been discussed in a detached or fragmentary manner, but which seems of sufficient importance to deserve a connected consideration.

It is familiarly known, that, in our progress from childhood to manhood, during the course of our education, and afterwards in the business of life, our belief, both speculative and practical, is, owing to our inability or unwillingness to investigate the subject for ourselves, often determined by the opinions of others. That the opinions of mankind should so often be formed in this manner, has been a matter of regret to many writers: others again have enforced the duty of submitting our convictions, in certain cases, to the guidance of fit judges; but all have admitted the wide extent to which the derivation of opinions upon trust prevails, and the desirableness that the choice of guides in these matters should be regulated by a sound discretion. It is, therefore, proposed to inquire how far our opinions may be properly influenced by the mere authority* of others,

* This use of the word authority is in accordance with its sense in classical writers. One of the meanings of auctoritas is explained by Facciolati, as follows: "Item pro pondere ac momento quod habent res legitime, sapienter, ac prudenter constitutæ, ut

independently of our own conviction founded upon appropriate reasoning.

When any one forms an opinion on a question either of speculation or practice, without any appropriate process of reasoning, really or apparently leading to that conclusion, and without compulsion or inducement of interest, but simply because some other persons, whom he believes to be competent judges on the matter, entertain that opinion, he is said to have formed his opinion upon authority.

If he is convinced by a legitimate process of reasoning -as by studying a scientific treatise on the subjecthis opinion does not rest upon authority. Or if he adopts any opinion, either sincerely or professedly, from motives of interest, or from fear of persecution, he does not found his opinion upon authority. He who believes upon authority, entertains the opinion simply because it is entertained by a person who appears to him likely to think correctly on the subject.

Whenever, in the course of this Essay, I speak of the

sunt leges, decreta senatus, responsa prudentum, res præclare gestæ, sententiæ clarorum virorum."-See Cic. Top. c. xix.

An auctor meant the originator or creator of anything. Hence Virgil speaks of the deified Augustus as "Auctorem frugum tempestatumque potentem," (Georg. i. 27;) and Sallust says that unequal glory attends "Scriptorem et auctorem rerum," (Cat. c. ii.) Hence any person who determines our belief, even as a witness, is called an auctor. Thus Tacitus, in quoting Julius Cæsar as a witness with respect to the former state of the Gauls, calls him "Summus auctorum," (Germ. c. 28,)—i. e., the highest of authorities. As writers, particularly of history, were the authorities for facts, "auctor" came to mean a writer. Hence Juvenal speaks of a preceptor of the Roman youth being required, "Ut legat historias, auctores noverit omnes, Tamquam ungues digitosque suos."-VII. 231. Compare Quintilian, Inst. Orat. I. 8, §. 18—21.

Principle of Authority, I shall understand the principle of adopting the belief of others, on a matter of opinion, without reference to the particular grounds on which that belief may rest.

In pursuing the inquiry, thus indicated in general terms, I shall attempt, first, to describe the circumstances under which opinions are usually derived from authority, and next, to ascertain the marks of sound or trustworthy authority in matters of opinion. Having shown what are the best indications of the competent judges in each subject, I shall inquire as to their numerical ratio to the rest of the community, and shall afterwards offer some remarks upon the application of the principle of authority to questions of civil government. Lastly, I shall make some suggestions upon the best means of creating a trustworthy authority in matters of opinion, and of guarding against the abuses to which the principle of authority is liable.

§ 3. It will be shown presently that a large proportion of the general opinions of mankind are derived merely from authority, and are entertained without any distinct understanding of the evidence on which they rest, or the argumentative grounds by which they are supported. Moreover, the advice of professional persons, or other competent judges in any subject matter, has great influence in questions of practice, both in public and private life. An inquiry, therefore, into the legitimate use of the principle of authority, and the consequences to which it tends, must be admitted to relate to an important subject. The importance of investigations in the field of logical science is undoubtedly far superior, inasmuch as logic furnishes the ultimate tests for the discovery of truth. The rules of logic, considered as an art, are a guide to the mind in the conduct