Pertness and ignorance may ask a question in three lines, which it will cost learning and ingenuity thirty pages to answer. When this is done, the same question shall be triumphantly asked again the next year, as if nothing had ever been written upon the subject. And as people in general, for one reason or another, like short objections better than long answers, in this mode of disputation (if it can be styled such) the odds must ever be against us; and we must be content with those for our friends who have honesty and erudition, candor and patience, to study both sides of the question — Be it so.
Of probable Reasoning.
The field of demonstration, as has been observed, is necessary truth; the field of probable reasoning is contingent truth, not what necessarily must be at all times, but what is, or was, or shall be.
No contingent truth is capable of strict demonstration; but necessary truths may sometimes have probable evidence.
Dr Wallis discovered many important mathematical truths, by that kind of induction which draws a general conclusion from particular premises. This is not strict demonstration, but, in some cases, gives as full conviction as demonstration itself; and a man may be certain, that a truth is demonstrable before it ever has been demonstrated. In other cases, a mathematical proposition may have such probable evidence from induction or analogy, as encourages the Mathematician to investigate its demonstration. But still the reasoning proper to mathematical and other necessary truths, is demonstration; and that which is proper to contingent truths, is probable reasoning.
These two kinds of reasoning differ in other respects. In demonstrative reasoning, one argument is as good as a thousand. One demonstration may be more elegant than another; it may be more easily comprehended, or it may be more subservient to some purpose beyond the present. On any of these accounts it may deserve a preference: But then it is sufficient by itself; it needs no aid from another; it can receive none. To add more demonstrations of the fame conclusion, would be a kind of tautology in reasoning; because one demonstration, clearly comprehended, gives all the evidence we are capable of receiving.
The strength of probable reasoning, for the most part, depends not upon any one argument, but upon many, which unite their force, and lead to the fame conclusion. Any one of them by itself would be insufficient to convince; but the whole taken together may have a force that is irresistible, so that to desire more evidence would be absurd. Would any man seek new arguments to prove that there were such persons as King Charles the First, or Oliver Cromwell?
Such evidence may be compared to a rope made up of many slender filaments twisted together. The rope has strength more than sufficient to bear the stress laid upon it, though no one of the filaments of which it w composed would be sufficient for that purpose.
It is a common observation, that it is unreasonable to require demonstration for things which do not admit of it. It is no less unreasonable to require reasoning of any kind for things which are known without reasoning. All reasoning must be grounded upon truths which are known without reasoning. In every branch of real knowledge there must be first principles whose truth is known intuitively, without reasoning, either probable or demonstrative. They are not grounded on reasoning, but all reasoning is grounded on them. It has been shown, that there are first principles of necessary truths, and first principles of contingent truths. Demonstrative reasoning is grounded upon the former, and probable reasoning upon the latter.
That we may not be embarrassed by the ambiguity of words, it is proper to observe, that there is a popular meaning of probable evidence, which ought not to be confounded with the philosophical meaning, above explained.
In common language, probable evidence is considered as an inferior degree of evidence, and is opposed to certainty: So that what is certain is more than probable, and what is only probable is not certain. Philosophers consider probable evidence, not as a degree, but as a species of evidence which is opposed, not to certainty, but to another species of evidence called demonstration.
Demonstrative evidence has no degrees; but probable evidence, taken in the philosophical sense, has all degrees, from the very least, to the greatest which we call certainty.
That there is such a city as Rome, I am as certain as of any proposition in Euclid ; but the evidence is not demonstrative, but of that kind which Philosophers call probable. Yet, in common language, it would found oddly to fay, it is probable there is such a city as Rome, because it would imply some degree of doubt or uncertainty.
Taking probable evidence, therefore, in the philosophical sense, as it is opposed to demonstrative, it may have any degrees of evidence, from the least to the greatest.
I think, in most cafes, we measure the degrees of evidence by the effect they have upon a found understanding, when comprehended clearly and without prejudice. Every degree of evidence perceived by the mind, produces a proportioned degree of assent or belief. The judgment may be in perfect suspense between two contradictory opinions, when there is no evidence for either, or equal evidence for both. The least preponderancy on one side inclines the judgment in proportion. Belief is mixed with doubt, more or less, until we come to the highest degree of evidence, when all doubt vanishes, and the belief is firm and immoveable. This degree of evidence, the highest the human faculties can attain, we call certainty.
Chap. in. but js itself of different kinds. The chief of these, I shall mention., without pretending to make a complete enumeration.
The first kind is that of human testimony, upon which the greatest part of human knowledge is built.
The faith of history depends upon it, as well as the judgment of solemn tribunals, with regard to mens acquired rights, and with regard to their guilt or innocence when they are charged with, crimes. A great part of the business of the Judge, of Counsel at the bar, of the Historian, the Critic, and the Antiquarian, is to canvass and weigh this kind of evidence ; and no man can act with common prudence in the ordinary occurrences of life, who has not some competent judgment of it.
The belief we give to testimony in many cases is not solely grounded upon the veracity of the testifier. In a single testimony, we consider the motives.a man might have to falsify. If there be no appearance of any such motive, much more if there be motives on the other side, his testimony has weight independent of his moral character. If the/ testimony be circumstantial, we consider how far the circumstances agree together, and with things that are known. It is so very difficult to fabricate a story, which cannot be detected by a judicious examination of the circumstances, that it acquires evidence, by being able to bear such a trial. There is an art in detecting false evidence in judicial proceedings, well known to able judges and barristers; so that I believe few false witnesses leave the bar without suspicion of their guilt..
When there is an agreement of many witnesses, in a great variety of circumstances, without the possibility of a previous con^ cert, the evidence may be equal to that of demonstration*
A second kind of probable evidence, is the authority of those who are good judges of the point in question. The supreme court
of judicature of the British nation, is often determined by the opinion of lawyers in a point of law, of physicians in a point of medicine, and of other artists, in what relates to their several professions. And, in the common affairs of life, we frequently rely upon the judgment of others, in points of, which we are not proper judges ourselves.
A third kind of probable evidence, is that by which we recognise the identity of things, and persons of our acquaintance: That two swords, two horses, or two persons, may be so perfectly alike, as not to be distinguishable by those to whom they are best known, cannot be shown to be impossible. But we learn either from nature, or from experience, that it never happens; or so, very rarely, that a person or thing, well known to us, is immediately recognised without any doubt, when we perceive the marks or signs by which we were in use to distinguish it from all other individuals of the kind..
This evidence we rely upon in the most important affairs of life; and, by this evidence, the identity, both of things and of persons, is determined in courts of judicature.
A fourth kind of probable evidence, is that which we have of mens future actions and conduct, from the general principles of action in man, or from our knowledge of the individuals..
Notwithstanding the folly and vice that is to be found among men, there is a certain degree of prudence and probity which we rely upon in every man that is not insane. If it were not so, no man would be safe in the company of another, and there could be no society among mankind. If men were, as much disposed to • hurt as to do good, to lie as to speak truth, they could not live together; they would keep at as great distance from one another as possible, and the race would soon perish.
We expect that men will take some care of themselves, of their family, friends, and reputation: That they will not injure others without some temptation: That they will have some gratitude for good offices, and some resentment of injuries.
Such maxims with regard to human conduct are the foundation of all political reasoning, and of common prudence in the conduct of life. Hardly can a man form any project in public or in private life, which does not depend upon the conduct of other men, as well as his own, and which does not go upon the supposition that men will act such a part in such circumstances. This evidence may be probable in a very high degree, but can never be demonstrative. The best concerted project may fail, and wife counsels may be frustrated, because some individual acted a part which it would have been against all reason to expect.
Another kind of probable evidence, the counterpart of the last, is that by which we collect mens characters and designs from their actions, speech, and other external signs.
We fee not mens hearts, nor the principles by which they are actuated ; but there are external signs of their principles and dispositions, which, though not certain, may sometimes be more trusted than their professions; and it is from external signs that we must draw all the knowledge we can attain of “men’s characters.
The next kind of probable evidence I mention, is that which Mathematicians call the probability of chances.
We attribute some events to chance, because we know only the remote cause which must produce some one event of a number; but know not the more immediate cause which determines a particular event of that number in preference to the others.
I think all the chances about which we reason in mathematics CHAP. Hi. are of this kind. Thus, in throwing a just die upon a table, we fay it is an equal chance which of the six sides shall be turned up; because neither the person who throws, nor the bystanders know the precise measure of force and direction necessary to turn up any one side rather than another. There are here therefore six events, one of which must happen; and as all are supposed to have equal probability, the probability of any one side being turned up, the ace, for instance, is as one to the remaining number five.
The probability of turning up two aces with two dice is as one to thirty-five; because here there are thirty-six events, each of which has equal probability.
Upon such principles as these, the doctrine of chances has furnished a field of demonstrative reasoning of great extent, although the events about which this reasoning is employed be not necessary, but contingent, and be not certain, but probable.
This may seem to contradict a principle before advanced, that contingent truths are not capable of demonstration; but it does not: For, in the mathematical reasonings about chance, the conclusion demonstrated, is not, that such an event shall happen, but that the probability of its happening bears such a ratio to the probability of its failing; and this conclusion is necessary upon the suppositions on which it is grounded.
The last kind of probable evidence I shall mention, is that by which the known laws of Nature have been discovered, and the effects which have been produced by them in former ages, or which may be expected in time to come.
The laws of Nature are the rules by which the Supreme Being governs the world. We deduce them only from facts that fall within our own observation, or are properly attested by those who have observed them.
The knowledge of some of the laws of Nature is necessary to all men in the conduct of life. These are soon discovered even by savages. They know that fire burns, that water drowns, that bodies gravitate towards the earth. They know that day and night, summer and winter, regularly succeed each other. As far back as their experience and information reach, they know that these have happened regularly; and, upon this ground, they are led, by the constitution of human nature, to expect that they will happen in time to come, in like circumstances.
The knowledge which the Philosopher attains of the laws of Nature differs from that of the vulgar, not in the first principles on which it is grounded, but in its extent and accuracy. He collects with care the phenomena that lead to the fame conclusion, and compares them with those that seem to contradict or to limit’ it. He observes the circumstances on which every phenomenon depends, and distinguishes them carefully from those that are accidentally conjoined with it. He puts natural bodies in various situations, and applies them to one another in various ways, oh purpose to observe the effect; and thus acquires from his fenses a more extensive knowledge of the course of Nature in a short time, than could be collected by casual observation in many ages.
But what is the result of his laborious researches? It is, that, as far as he has been able to observe, such things have always happened in such circumstances, and such bodies have always been found to have such properties. These are matters of fact, attested by fense, memory and testimony, just as the few facts which the vulgar know are attested to them.
And what conclusions does the Philosopher draw from the facts he has collected? They are, that like events have happened in former times in like circumstances, and will happen in time to come; and these conclusions are built on the very fame ground on which the simple rustic concludes that the fun will rife to-morrow.
Facts reduced to general rules, and the consequences of those general rules, are all that we really know of the material world. And the evidence that such general rules have no exceptions, as well as the evidence that they will be the fame in time to come as they have been in time past, can never be demonstrative. It is only that species of evidence which Philosophers call probable. General rules may have exceptions or limitations which no man ever had occasion to observe. The laws of Nature may be changed by him who established them. But we are led by our constitution to rely upon their continuance with as little doubt as if it was demonstrable.
I pretend not to have made a complete enumeration of all the kinds of probable evidence; but those I have mentioned are sufficient to show, that the far greatest part, and the most interesting part of our knowledge, must rest upon evidence of this kind; and that many things are certain for which we have only that kind of evidence which Philosophers call probable.
We have no reason to ascribe intelligence, or even sensation, to plants; yet there appears in them an active force and energy, which cannot be the result of any arrangement or combination of inert matter. The same thing may be said of those powers by which animals are nourished and grow, by which matter gravitates, by which magnetical and electrical bodies attract and repel each other, and by which the parts of solid bodies cohere.
The mind of man is the noblest work of God which reason discovers to us, and therefore, on account of its dignity, deserves our study. It must, indeed, be acknowledged, that although it is of all objects the nearest to us, and seems the most within our reach, it is very difficult to attend to its operations, so as to form a distinct notion of them; and on that account there is no branch of knowledge in which the ingenious and speculative have fallen into so great errors, and even absurdities. These errors and absurdities have given rise to a general prejudice against all inquiries of this nature; and because ingenious men have, for many ages, given different and contradictory accounts of the powers of the mind, it is concluded that all speculations concerning them are chimerical and visionary. But whatever effect this prejudice may have with superficial thinkers, the judicious will not be apt to be carried away with it.
Mr. Hume has justly observed, that “all the sciences have a relation to human nature; and, however wide any of them may seem to run from it, they still return back by one passage or another. This is the centre and capitol of the sciences, which being once masters of, we may easily extend our conquests everywhere.” The faculties of our minds are the tools and engines we must use in every disquisition; and the better we understand their nature and force, the more successfully we shall be able to apply them.
By the mind of a man we understand that in him which thinks, remembers, reasons, wills. The essence both of body and of mind is unknown to us. We know certain properties of the first, and certain operations of the last, and by these only we can define or describe them. We define body to be that which is extended, solid, movable, divisible. In like manner we define mind to be that which thinks. We are conscious that we think, and that we have a variety of thoughts of different kinds; such as seeing, hearing, remembering, deliberating, resolving, loving, hating, and many other kinds of thought, all which we are taught by nature to attribute to one internal principle; and this principle of thought we call the mind or soul of a man.
To body we ascribe various properties, but not operations, properly so called; it is extended, divisible, movable, inert; it continues in any state in which it is put; every change of its state is the effect of some force impressed upon it, and is exactly proportional to the force impressed, and in the precise direction of that force. These are the general properties of matter, and these are not operations; on the contrary, they all imply its being a dead, inactive thing, which moves only as it is moved, and acts only by being acted upon. But the mind is, from its very nature, a living and active being. Every thing we know of it implies life and active energy; and the reason why all its modes of thinking are called its operations is, that in all, or in most of them, it is not merely passive, as body is, but is really and properly active. In all ages, and in all languages, ancient and modern, the various modes of thinking have been expressed by words of active signification, such as seeing, hearing, reasoning, willing, and the like. It seems, therefore, to be the natural judgment of mankind, that the mind is active in its various ways of thinking; and for this reason they are called its operations, and are expressed by active verbs. It may be made a question, What regard is to be paid to this natural judgment? May it not be a vulgar error? Philosophers who think so have, no doubt, a right to be heard. But until it is proved that the mind is not active in thinking, but merely passive, the common language with regard to its operations ought to be used, and ought not to give place to a phraseology invented by philosophers, which implies its being merely passive.
In 1784, a bill was before the House of Delegates of Virginia for a publick Act, “establishing a provision for the teachers of the Christian religion,” which had for its object the compelling of every person to contribute to some religious teacher. The bill was postponed to the next session of the legislature and ordered to be printed, and the people were requested to signify their opinion respecting its adoption. Among the numerous remonstrances against the passage of this bill, the following one drawn by Mr. Madison, stands pre-eminent. It is certainly one of the ablest productions of that great statesman, and deserves to be widely circulated. To use the language of the authour of the work from which it is extracted — Benedict’s “General History of the Baptist denomination in America,” — its “style is elegant and perspicuous and for strength of reasoning and purity of principle, it has seldom been equalled, certainly never surpassed, by anything on the subject in the English language.” It is hardly necessary to say that the bill never passed the House. ~ Hartford Times
The difficulty which the mere thought of this problem puts before our eyes is this. Man is an animal which, if it lives among others of its kind, requires a master. For he certainly abuses his freedom with respect to other men, and although as, a reasonable being he wishes to have a law which limits the freedom of all, his selfish animal impulses tempt him, where possible, to exempt himself from them. He thus requires a master, who will break his will and force him to obey a will that is universally valid, under which each can be free. But whence does he get this master? Only from the human race. But then the master is himself an animal, and needs a master. Let him begin it as he will, it is not to be seen how he can procure a magistracy which can maintain public justice and which is itself just, whether it be a single person or a group of several elected persons. For each of them will always abuse his freedom if he has none above him to exercise force in accord with the laws. The highest master should be just in himself, and yet a man. This task is therefore the hardest of all; indeed, its complete solution is impossible, for from such crooked wood as man is made of, nothing perfectly straight can be built.
Whatever concept one may hold, from a metaphysical point of view, concerning the freedom of the will, certainly its appearances, which are human actions, like every other natural event are determined by universal laws. However obscure their causes, history, which is concerned with narrating these appearances, permits us to hope that if we attend to the play of freedom of the human will in the large, we may be able to discern a regular movement in it, and that what seems complex and chaotic in the single individual may be seen from the standpoint of the human race as a whole to be a steady and progressive though slow evolution of its original endowment. Since the free will of man has obvious influence upon marriages, births, and deaths, they seem to be subject to no rule by which the number of them could be reckoned in advance. Yet the annual tables of them in the major countries prove that they occur according to laws as stable as [those of] the unstable weather, which we likewise cannot determine in advance, but which, in the large, maintain the growth of plants the flow of rivers, and other natural events in an unbroken uniform course. Individuals and even whole peoples think little on this. Each, according to his own inclination, follows his own purpose, often in opposition to others; yet each individual and people, as if following some guiding thread, go toward a natural but to each of them unknown goal; all work toward furthering it, even if they would set little store by it if they did know it.