Part II.

The subdivisions of moral reasoning.....I. Experience.

a full and uniform experience. That, in the last week of December next, it will snow in any part of Britain specified, is perhaps probable; that is, if, on inquiry or recollection, we are satisfied that this hath more frequently happened than the contrary that some time in that month it will snow, is more probable, but not certain; because, though this conclusion be founded on expérience, that experience is not uniform: lastly, that it will snow some time during winter, will, I believe, on the same principles, be pronounced certain.

Ir was affirmed, that experience, or the tendency of the mind to associate ideas under the notion of causes, effects, or adjuncts, is never contracted by one. example only. This assertion, it may be thought, is contradicted by the principle on which physiologists commonly proceed, who consider one accurate expériment in support of a particular doctrine as sufficient evidence. The better to explain this phenomenon, and the farther to illustrate the nature of experience, I shall make the following observations. First, where as sense and meinory are conversant only about individuals, our earliest experiences imply, or perhaps generate, the notion of a species, including all those individuals, which have the most obvious and universal fesemblance. From Charles, Thomas, William, we ascend to the idea of man; from Britain, France, Spain, to the idea of kingdom. As our acquaintance with nature enlarges, we discover resemblances of a striking and important nature, between one species

Sect. II.

Of deductive evidence.

and another, which naturally begets the notion of a genus. From comparing men with beasts, birds, fishes, and reptiles, we perceive that they are all alike possessed of life, or a principle of sensation and action, and of an organised body, and hence acquire the idea of animal; in like manner, from comparing kingdoms with republics and aristocracies, we obtain the idea of nation, and thence again rise in the same track to ideas still more comprehensive. Further, let it be remem-' bered, that by experience we not only decide concerning the future from the past, but concerning things uncommon from things familiar, which resemble them.

Now, to apply this observation: a botanist, in traversing the fields, lights on a particular plant, which appears to be of a species he is not acquainted with. The flower he observes is monopetalous, and the number of flowers it carries is seven. Here are two facts that occur to his observation, let us consider in what way he will be disposed to argue from them. From the first he does not hesitate to conclude, not only as probable, but as certain, that this individual, and all of the same species, invariably produce monopetalous flowers. From the second, he by no means concludes, as either certain, or even probable, that the flowers which either this plant, or others of the same species, carry at once, will always be seven. This difference, to a superficial inquirer, might seem capricious, since there appears to be one example, and but one in either case, on which the conclusion can be founded. The truth is, that it is not from this example only that he

Part III.

The subdivisions of moral reasoning.....I. Experience.

deduces these inferences. Had he never heretofore taken the smallest notice of any plant, he could not have reasoned at all from these remarks. The mind recurs instantly from the unknown, to all the other known species of the same genus, and thence to all the known genera of the same order or tribe; and having experienced in the one instance, a regularity in every species, genus, and tribe, which admits no exception; in the other, a variety as boundless as is that of season, soil, and culture; it learns hence to mark the difference.

4

AGAIN, we may observe, that, on a closer acquaintance with those objects wherewith we are surrounded, we come to discover that they are mostly of a compound nature, and that not only as containing a complication of those qualities called accidents, as gravity, mobility, colour, extension, figure, solidity, which are common almost to all matter, not only as consisting of different members, but as comprehending a mixture of bodies, often very different in their nature and properties, as air, fire, water, earth, salt, oil, spirit, and the like. These, perhaps, on deeper researches, will be found to consist of materials still simpler. Moreover, as we advance in the study of Nature, we daily find more reason to be convinced of her constancy in all her operations, that like causes in like circumstances always produce like effects, and inversely like effects always flow from like causes. The in constancy which appears at first in some of Nature's works, a more improved experience teacheth us to ac

count for in this manner. As most of the objects we know, are of a complex nature, on a narrower scrutiny we find, that the effects ascribed to them, ought often solely to be ascribed to one or more of the component parts; that the other parts noway contribute to the production; that, on the contrary, they sometimes tend to hinder it. If the parts in the composition of similar objects were always in equal quantity, their being compounded would make no odds; if the parts, though not equal, bore always the same proportion to the whole, this would make a difference; but such as in many cases might be computed. In both respects, however, there is an immense variety. Perhaps every individual differs from every other individual of the same species, both in the quantities and in the proportions of its constituent members and component parts. This diversity is also found in other things, which, though hardly reducible to species, are generally known by the same name. The atmosphere, in the same place, at different times, or at the same time in different places, differs in density, heat, humidity, and the number, quality, and proportion of the vapours or particles with which it is loaden. The more then we become acquainted with elementary natures, the more we are ascertained by a general experience of the uniformity of their operations. And though perhaps it be impossible for us to attain the knowledge of the simplest elements of any body, yet, when any thing appears so simple, or rather so exactly uniform, as that we have observed it invariably to. produce similar effects; on discovering any new effect,

Part IIL

The subdivisions of moral reasoning.....I. Experience.

though but by one experiment, we conclude, from the general experience of the efficient, a like constancy in this energy as in the rest. Fire consumes wood, melts copper, and hardens clay, In these instances it acts uniformly, but not in these only. I have always experienced hitherto, that whatever of any species is consumed by it once, all of the same species it will consume upon trial at any time. The like may be said of what is melted, or hardened, or otherwise altered, by it. If then, for the first time, I try the influence of fire on any fossil, or other substance; whateyer be the effect, I readily conclude, that fire will always produce a similar effect on similar bodies. This conclusion is not founded on this single instance, but on this instance compared with a general experience of the regularity of this element in all its operations.

So much for the first tribe, the evidence of experience, on which I have enlarged the more, as it is, if not the foundation, at least the criterion of all moral reasoning whatever. It is, besides, the principal organ of truth in all the branches of physiology, (I use the word in its largest acceptation) including natural history, astronomy, geography, mechanics, optics, hydrostatics, meteorology, medicine, chymistry. Under the general term I also comprehend natural theology and psychology, which, in my opinion, have been most unnaturally disjoined by philosophers. Spirit, which here comprises only the Supreme Being and the human soul, is surely as much included under the notion of natural object, as body is, and is knowable to the