we believe, after a thousand experiments, that a ftone will fall, or fire burn; can we ever fatisfy ourselves concerning any determination, which we may form, with regard to the origin of worlds, and the fituation of nature, from, and to eternity?

This narrow limitation, indeed, of our enquiries, is, in every respect, fo reasonable, that it fuffices to make the flighteft examination into the natural powers of the human mind, and to compare them with their objects, in order to recommend it to us. We fhall then find what are the proper subjects of science and enquiry.

It seems to me, that the only objects of the abstract fciences or of demonftration are quantity and number, and that all attempts to extend this more perfect fpecies of knowledge beyond these bounds are mere fophiftry and illufion. As the component parts of quantity and number are entirely fimilar, their relations become intricate and involved; and nothing can be more curious, as well as useful, than to trace, by a variety of mediums, their equality or inequality, through their different appearances. But as all other ideas are clearly diftinct and different from each other, we can never advance farther,. by our outmoft fcrutiny, than to obferve this diverfity, and, by an obvious reflection, pronounce one thing not to be another. Or if there be any difficulty in these decifions, it proceeds entirely from the undeterminate meaning of words, which is corrected by jufter definitions. That the fquare of the hypothenufe is equal to the Squares of the other two fides, cannot be known, let the terms be ever fo exactly defined, without a train of reafoning and enquiry. But to convince us of this propofition, that where there is no property, there can be no injuftice, it is only neceflary to define the terms, and explain injuftice to be a violation of property. This propofition

N 3

pofition is, indeed, nothing but a more imperfect definition. It is the fame cafe with all thofe pretended fyllogiftical reasonings, which may be found in every other branch of learning, except the sciences of quantity and number; and thefe may fafely, I think, be pronounced the only proper objects of knowledge and demonftration.

All other enquiries of men regard only matter of fact and existence; and these are evidently incapable of demonftration. 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 exiftence. The propofition, which affirms it not to be, however falfe, is no lefs conceivable and intelligible, than that which affirms it to be. The cafe is different with the fciences, properly fo called. Every propofition, which is not true, is there confused and unintelligible. That the cube root of 64 is equal to the half of 10, is a falfe propofition, and can never be diftinctly conceived. But that CESAR, or the angel GABRIEL, or any being never exifted, may be a falfe propofition, but ftill is perfectly conceivable, and implies no contradiction.

The existence, therefore, of any being can only be proved by arguments from its caufe or its effect; and thefe arguments are founded entirely on experience. If we reafon à priori, any thing may appear able to produce any thing. The falling of a pebble may, for ought we know, extinguish the fun; or the wifh of a man controul the planets in their orbits. It is only experience, which tea hes us the nature and bounds of cause and effect, and enables us to infer the existence of one object from that of another*. Such is the foundation of mo

See NOTE [Q].

ral

ral reasoning, which forms the greatest part of human knowledge, and is the fource of all human action and behaviour.

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

The sciences, which treat of general facts, are politics, natural philofophy, phyfic, chymiftry, &c. where the qualities, causes, and effects of a whole fpecies of objects are enquired into.

Divinity or Theology, as it proves the exiftence of a Deity, and the immortality of fouls, is compofed partly of reasonings concerning particular, partly concerning general facts. It has a foundation in reafon, so far as it is fupported by experience. But its beft and most folid foundation is faith and divine revelation.

Morals and criticifm are not fo properly objects of the understanding as of taste and sentiment. Beauty, whether moral or natural, is felt, more properly than perceived. Or if we reafon concerning it, and endeavour to fix its ftandard, we regard a new fact, viz. the general taste of mankind, or fome fuch fact, which may be the object of reasoning and enquiry.

When we run over libraries, perfuaded of these principles, what havoc must we make? If we take in our hand any volume; of divinity or school metaphyfics, for inftance; let us afk, Does it contain any abstract reafoning concerning quantity or number? No. Does it contain any experimental reasoning concerning matter of fact and exiftence? No. Commit it then to the flames: For it can contain nothing but fophiftry and illufion.

N 4

A

DISSERTATION

ΟΝ ΤΗ Ε

PASSIONS.

1.SOM

SECT. I.

OME objects produce immediately an agreeable fenfation, by the original ftructure of our organs, and are thence denominated GOOD; as others, from their immediate disagreeable sensation, acquire the appellation of EVIL. Thus moderate warmth is agreeable and good; exceffive heat painful and evil.

Some objects again, by being naturally conformable or contrary to paffion, excite an agreeable or painful fenfation; and are thence called Good or Evil. The punishment of an adversary, by gratifying revenge, is good; the sickness of a companion, by affecting friendship, is evil.

2. All good or evil, whence-ever it arifes, produces various paffions and affections, according to the light in which it is furveyed.

When good is certain or very probable, it produces Joy: When evil is the fame fituation, there arifes GRIEF or SORROW.

When