knowledge of the grounds on which they rest. We shall now attempt to distinguish the cases in which this mode of forming opinions is properly applicable, and thus to determine the proper province of authority. As a first step in this inquiry, it will be necessary to consider what are the marks by which trustworthy authority in matters of opinion may be recognised, and what are the qualifications of a competent guide in questions of speculative truth and practical conduct. CHAPTER III. ON THE MARKS OF TRUSTWORTHY AUTHORITY. § 1. In the first chapter, we adverted to the received distinction between matters of fact and matters of opinion; and we showed that, although this distinction may be wanting in scientific precision, it nevertheless classifies the objects of belief in a manner suitable to the purposes of this Essay. Before, therefore, we proceed to enumerate the marks of trustworthy authority in matters of opinion, it will be convenient to ascertain the marks of trustworthy testimony in matters of fact, and to compare the qualifications which render a person a credible witness with those which give weight to a person's opinion, as such, independently of his reasons. The credibility of a witness to a fact seems to depend mainly on the four following conditions: viz. 1. That the fact fell within the range of his senses. 2. That he observed or attended to it. 3. That he possesses a fair amount of intelligence and memory. 4. That he is free from any sinister or misleading interest; or if not, that he is a person of veracity. If a person was present at any event, so as to see or hear it; if he availed himself of his opportunity, so as to take note of what passed; if he has sufficient mental capacity to give an accurate report of the occurrence; and if he is not influenced by personal favour, or dislike, or fear, or the hope of gain, to misreport the fact; or if, notwithstanding such influence, his own conscience and moral or religious principle, or the fear of public opinion, deters him from mendacity, such a person is a credible witness. Upon considering these conditions for veracious testimony, we see that, with respect to statements of fact, everything depends on the source from which they emanate. They rest entirely on But with argu the credit due to known or assignable witnesses. ments it is different. They have a probative force quite independent of the person by whom they are invented or propounded. They depend on the relation of premises and conclusion, of antecedent and consequent. For the truth of his premises the author of an argument may be personally responsible; but the sequence of his conclusion is a matter quite independent of his individual veracity. Logic, therefore, as a science, or art, of reasoning, has no concern with moral character; all arguments, as arguments, and reduced to their bare logical elements, are equally conclusive, whatever may be the source from which they proceed. Thus, in judicial proceedings, an advocate may argue with equal force on either side of a question, though without any personal conviction on the subject. He may handle arguments (as a fencer handles his sword) with the skill of a practised disputant, regarding them merely as instruments for the attainment of his end, but without making himself responsible for the soundness of his conclusions.1 So a person may, as a rhetorical exercise, or for the purpose of eliciting the truth by the juxta-position of conflicting views, compose an argument on opposite sides of a question. Examples of this species of composition are afforded by all writings in the form of a controversial dialogue, such as the dialogues of Plato and Cicero and the Minute Philosopher of Berkeley. A person who produces an argument, produces something which can be judged without reference to himself, and which is not necessarily either confirmed or enfeebled by his individual qualities or circumstances. A new demonstration of a mathematical problem would in no way depend on the character of its inventor. But the witness to a fact can only depose truly to that fact; he cannot, like the arguer, choose his ground hypothetically; and the credibility of his testimony depends solely on his own personal circumstances and moral character. § 2. Anonymous testimony to a matter of fact, is therefore wholly devoid of weight; unless, indeed, there be circumstances 1 'Sir James Johnston happened to say that he paid no regard to arguments of counsel at the bar of the House of Commons, because they were paid for speaking. JOHNSON: "Nay, sir, argument is argument. You cannot help paying regard to their arguments, if they are good. If it were testimony, you might disregard it, if you knew that it were purchased. There is a beautiful image in Bacon upon this subject: Testimony is like an arrow shot from a long-bow-the force of it depends on the strength of the hand that draws it; argument is like an arrow from a cross-bow, which has great force though shot by a child.'"'-BOSWELL'S Johnson,, vol. viii. p. 281. which render it probable that a trustworthy witness has adequate motives for concealment, or extraneous circumstances may support and accredit a statement, which, left to itself, would fall to the ground. Thus an anonymous communication may put a man on his guard, or may induce him to make inquiries in a certain direction, when it appears probable from the contents of the communication, or from other circumstances, that it may proceed from some quarter in which secrecy is rendered inevitable by a powerful interest. Such was the letter to Lord Monteagle concerning the Gunpowder Plot; such are threatening letters, or letters giving private information respecting the conduct of individuals, in a public or private capacity. Occasionally, it happens that important suggestions are conveyed in this manner; but, for the most part, information given anonymously turns out, on investigation, to be utterly worthless. An anonymous work, too, may sometimes exhibit internal evidence of truth; that is, there may be certain marks in the writing which give it an air of veracity, though the author may have deemed it prudent to withhold his name from the public. It is in this manner that anonymous statements of facts in newspapers are authenticated: the periodical appearance of the newspaper and the character which its management may have acquired for correctness of intelligence, serving as guarantees for the truth of its statements.1 Statements in an anonymous publication may likewise acquire credibility from their remaining uncontradicted by persons who have an interest in contradicting them, and are acquainted with the facts of the It may be added that a work may be anonymous, from the loss of the author's name, though its original publication may not have been anonymous. For instance, the Acts of the Apostles, and many chronicles of the middle ages, are now anonymous, though there is no reason to suppose that the authors concealed their names from their contemporaries. case. With these exceptions-which are rather apparent than real -it is essential to testimony that we should know the witness as well as the fact, and be able to estimate his individual qualifications, as a testifier or relator. Whereas, in the case of an argument, its conclusiveness, considered without reference to the truth of its premises, and judged merely by logical rules, is wholly independent of its author. 1 See this subject further pursued in Chapter IX. This independence of an argument with respect to the character of its author, implies, however, both that its inferential force is thoroughly understood, and that the truth of its premises is conceded. Whenever this is not the case, the character of the person who advances the argument is a most material consideration; and it is to cases of this sort that our present inquiry relates-that is to say, to cases where an opinion is accepted out of confidence in the person who holds it, and without any full comprehension of its grounds. § 3. It may be added that for all purposes of philosophical observation, a knowledge of the proper science, and a peculiar training of the senses, are requisite, and therefore that a witness who possesses these qualifications is far more credible than one who is destitute of them. For example, a scientific naturalist who reports that he has seen an undescribed animal or vegetable in a remote country, is far less likely to be mistaken than a common traveller, ignorant of natural history. A skilled witness of this sort may be considered, in a certain sense, as a witness of authority, inasmuch as his previous study and habits of observation give a peculiar weight to his report of the phenomenon. § 4. The distinction between testimony, argument, and authority, may be briefly summed up thus: In questions of testimony, I believe a matter of fact, because the witness believes it. In questions of argument, I believe the conclusion to be true, because it is proved by reasons satisfactory to my understanding. In questions of authority, I believe a matter of opinion, because it is believed by a person whom I consider a competent judge of the question. § 5. Now, on looking at the qualities which render anyone a credible witness to a matter of fact, we may remark that they are of common occurrence. For testimony, nothing further is in general required than opportunity of observation, ordinary attention and intelligence, and veracity. Almost every person of sound mind, who has reached a certain age, is a credible witness as to matters which he has observed, and as to which he has no immediate interest in deception or concealment.' For purposes of 1 For the administration of justice, it is important that there should be some recognised tests of the credibility of witnesses to facts in dispute before the court. In almost all systems of judicial procedure, an attempt has been made to lay down |