Section XII132. All other enquiries of men regard only matter of fact and existence; and these are evidently incapable of demonstration. Whatever is may not be. No negation of a fact can involve a contradiction. The non-existence of any being, without exception, is as clear and distinct an idea as its existence. The proposition, which affirms it not to be, however false, is no less conceivable and intelligible, than that which affirms it to be. The case is different with the sciences, properly so called. Every proposition, which is not true, is there confused and unintelligible. That the cube root of 64 is equal to the half of 10, is a false proposition, and can never be distinctly conceived. But that Caesar, or the angel Gabriel, or any being never existed, may be a false proposition, but still is perfectly conceivable, and implies no contradiction.

The existence, therefore, of any being can only be proved by arguments from its cause or its effect; and these arguments are founded entirely on experience. If we reason a priori, anything may appear able to produce anything. The falling of a pebble may, for aught we know, extinguish the sun; or the wish of a man control the planets in their orbits. It is only experience, which teaches us the nature and bounds of cause and effect, and enables us to infer the existence of one object from that of another[34]. Such is the foundation of moral reasoning, which forms the greater part of human knowledge, and is the source of all human action and behaviour.

[34] That impious maxim of the ancient philosophy, Ex nihilo, nihil fit, by which the creation of matter was excluded, ceases to be a maxim, according to this philosophy. Not only the will of the supreme Being may create matter; but, for aught we know a priori, the will of any other being might create it, or any other cause, that the most whimsical imagination can assign.

Moral reasonings are either concerning particular or general facts. All deliberations in life regard the former; as also all disquisitions in history, chronology, geography, and astronomy.

The sciences, which treat of general facts, are politics, natural philosophy, physic, chemistry, &c. where the qualities, causes and effects of a whole species of objects are enquired into.

Divinity or Theology, as it proves the existence of a Deity, and the immortality of souls, is composed partly of reasonings concerning particular, partly concerning general facts. It has a foundation in reason, so far as it is supported by experience. But its best and most solid foundation is faith and divine revelation.

Morals and criticism are not so properly objects of the understanding as of taste and sentiment. Beauty, whether moral or natural, is felt, more properly than perceived. Or if we reason concerning it, and endeavour to fix its standard, we regard a new fact, to wit, the general tastes of mankind, or some such fact, which may be the object of reasoning and enquiry.

When we run over libraries, persuaded of these principles, what havoc must we make? If we take in our hand any volume; of divinity or school metaphysics, for instance; let us ask, Does it contain any abstract reasoning concerning quantity or number? No. Does it contain any experimental reasoning concerning matter of fact and existence? No. Commit it then to the flames: for it can contain nothing but sophistry and illusion.

INDEX

Abstraction not source of ideas of primary qualities, 122.

Academic philosophy, 34.

Action and philosophy, 1, 4, 34, 128;

Addition 4.

Analogy a species of, the foundation of all reasoning about matter of fact, 82;

Animals the reason of, 83-85; learn from experience and draw inferences, 83; which can only be founded on custom, 84; cause of difference between men and animals, 84 n.

Antiquity 62.

Appearances to senses must be corrected by reason, 117.

A priori 25, 36 n, 89 n, 132, 132 n.

Aristotle 4.

Association of ideas, three principles of, 18-19, 41-44 (v. Cause C).

Atheism 116.

Bacon 99.

Belief (v. Cause C, 39-45); and chance, 46.

Berkeley really a sceptic, 122 n.

Bigotry 102.

Body and soul, mystery of union of, 52; volition and movements of, 52.

Real existence of (v. Scepticism, B, 118-123).

Cause first (v. God, Necessity, 78-81; Providence, 102-115, 132 n). a principle of association of ideas, 19, 43; sole foundation of reasonings about matter of fact or real existence, 22.

A. Knowledge of Causes arises from experience not from Reason, 23-33.

Reasonings a priori give no knowledge of cause and effect, 23 f.; impossible to see the effect in the cause since they are totally different, 25; natural philosophy never pretends to assign ultimate causes, but only to reduce causes to a few general causes, e.g. gravity, 26; geometry applies laws obtained by experience, 27.

Conclusions from experience not based on any process of the understanding, 28; yet we infer in the future a similar connexion between known qualities of things and their secret powers, to that which we assumed in the past. On what is this inference based? 29; demonstrative reasoning has no place here, and all experimental reasoning assumes the resemblance of the future to the past, and so cannot prove it without being circular, 30, 32; if reasoning were the basis of this belief, there would be no need for the multiplication of instances or of long experience, 31; yet conclusions about matter of fact are affected by experience even in beasts and children, so that they cannot be founded on abstruse reasoning, 33; to explain our inferences from experience a principle is required of equal weight and authority with reason, 34.

B. Custom enables us to infer existence of one object from the appearance of another, 35-38.

Experience enables us to ascribe a more than arbitrary connexion to objects, 35; we are determined to this by custom or habit which is the great guide of human life, 36; but our inference must be based on some fact present to the senses or memory, 37; the customary conjunction between such an object and some other object produces an operation of the soul which is as unavoidable as love, 38; animals also infer one event from another by custom, 82-84; and in man as in animals experimental reasoning depends on a species of instinct or mechanical power that acts in us unknown to ourselves, 85.

C. Belief, 39-45. Belief differs from fiction or the loose reveries of the fancy by some feeling annexed to it, 39; belief cannot be defined, but may be described as a more lively, forcible, firm, steady conception of an object than can be attained by the imagination alone, 40; it is produced by the principles of association, viz. resemblance, 41; contiguity, 42; causation, 43; by a kind of pre-established harmony between the course of nature and our ideas, 44; this operation of our minds necessary to our subsistence and so entrusted by nature to instinct rather than to reasoning, 45.

Probability, 46-7.

Belief produced by a majority of chances by an inexplicable contrivance of Nature, 46 (cf. 87-8); probability of causes: the failure of a cause ascribed to a secret counteracting cause, 47 (cf. 67); it is universally allowed that chance when strictly examined is a mere negative word, 74.

D. Power, 49-57.

Power, force, energy, necessary connexion must either be defined by analysis or explained by production of the impression from which they are copied, 49; from the first appearance of an object we cannot foretell its effect: we cannot see the power of a single body: we only see sequence, 50.

Is the idea of power derived from an internal impression and is it an idea of reflection? 51; it is not derived, as Locke said, from reasoning about power of production in nature, 50 n; nor from consciousness of influence of will over bodily organs, 52; nor from effort to overcome resistance, 52 n (cf. 60 n); nor from influence of will over mind, 53; many philosophers appeal to an invisible intelligent principle, to a volition of the supreme being, and regard causes as only occasions and our mental conceptions as revelations, 54-5; thus diminishing the grandeur of God, 56; this theory too bold and beyond verification by our faculties, and is no explanation, 57; vis inertiae, 57 n.

In single instances we only see sequence of loose events which are conjoined and never connected, 58; the idea of necessary connexion only arises from a number of similar instances, and the only difference between such a number and a single instance is that the former produces a habit of expecting the usual attendant, 59, 61. This customary transition is the impression from which we form the idea of necessary connexion.

E. Reasoning from effect to cause and conversely, 105-115 (v. Providence).

In arguing from effect to cause we must not infer more qualities in the cause than are required to produce the effect, nor reason backwards from an inferred cause to new effects, 105-8; we can reason back from cause to new effects in the case of human acts by analogy which rests on previous knowledge, 111-2; when the effect is entirely singular and does not belong to any species we cannot infer its cause at all, 115.