A Logic of Facts; Or, Every-day Reasoning

by George Jacob Holyoake

These truths of intuition or consciousness are the foundation of all knowledge. Truths which we know, by way of inference, are occurrences which took place while we were absent—the events of history and the theorems of mathematics. But the truths known by intuition are the original premises from which all others axe inferred. Our assent to the conclusion being grounded upon the truth of the premises, we could never arrive at any knowledge by reasoning, unless something could be known antecedently to all reasoning.

'Whatever is known to us by consciousness, is known beyond possibility of question. What one sees, or feels, whether bodily or mentally, one cannot but be sure that one sees or feels. No science is required for the purpose of establishing such truths; no rules of art can render our knowledge of them more certain than it is in itself. There is no logic for this portion of our know ledge.'*

All discussions pertaining to the nature and limits of intuition or consciousness are referred to the higher or transcendental metaphysics, but all the facts that compose evidence and become the grounds of inference are, according to the view taken here, necessarily subjects of examination.

'Cogito ergo sum—I think, therefore I am, argued Des Cartes. We learn by this that consciousness of the operations of the mind is the strongest evidence of our existence. It cannot be proved so forcibly by any other means; and although Des Cartes' language may appear to involve a logical fallacy, yet the proof of our personal existence which we have from thinking, is the fullest and best we are acquainted with.'**

* J. 8. Mil: Logic, vol. l, p. 7.
** Rev. Robert Amalie.

There is a numerous class of facts from which all men draw conclusions, which facts are not referable to the evidence of the senses. There are the facts of testimony. Testimony is founded on laws almost as fixed and certain as those of nature. All our knowledge, scientific, literary, historical—all except what arises from our experience and consciousness—depends on it. In the administration of justice it is the sole guardian of property and life. If a man of known integrity and veracity state a fact, without any possible motive of self-interest, and evidently subject to no delusion; and if others of like character, who could have no understanding or collusion with him, state the same, men are nearly as certain of it as of any truth in mathematics. I believe in the existence of Rome and the facts of astronomy on this evidence, although I never saw the city or examined the stars through a telescope.

The conclusiveness of testimony is designated moral certainty. The value of testimony depends on three things. 1. On the nature of the subject. Some subjects are capable of more accurate observation than others. 2. On the powers and character of the observer—his ability to understand or note that of which he testifies—and his honesty in common matters. 3. On the number of our informers. Several persons are less likely to be imposed upon than one.

Testimony or moral certainty is inferior to physical certainty. A physical certainty bears uniformly the name of certainty, while a moral certainty is characterised as a probability. Great, very great may be the probability, still it is less in reliableness than a physical certainty. The evidence of Cato or Aristides would be very conclusive—yet somewhat less certain than that which our own senses have proved.

The conclusions from moral certainties are obtained like other conclusions, by induction. The induction from moral facts is like the induction from physical facts, with this difference—that the conclusions from moral facts are probabilities, like the facts on which they are founded. Whatever has physical certainty in its favour is considered demonstrable, and when sufficient probable evidence is adduced in favour of a proposition, it is considered to be fairly proved. Some persons, biased by the strictness of mathematical proof, insist upon the same accuracy in moral investigations. I have elsewhere pointed out the juvenility and infatuation of this error. Insist upon demonstration where the nature of the questions admits it. Less should not, in such case, suffice. Accept probability where probability is the sole evidence attainable. Never ask more than reason can grant. We must admit gradations of validity. What we are conscious of, we know. All we receive on testimony, we believe. Physical certainty is knowledge: moral certainty, belief. Hume remarks, in his 'Essay on Probabilities,' that 'Mr. Locke divides all arguments into demonstrative and probable. In this view, we must say, that it is only probable all men must die, or that the sun will rise to-morrow. But to conform our language more to common us, we ought to divide arguments into demonstrations, proofs, and probabilities. By proofs, meaning such arguments from experience as leave no room for doubt or opposition.'*

* Hume's Essays, vol. 2, p.59.