in various ages. diftinguished by thefe very oppofite characters. It is therefore by due cultivation, and proper diligence, that we increase the vigour of our minds, and carry reafon to perfection. Where this method is followed, the intellect acquires strength, and knowledge is enlarged in every direction: where it is neglected, we remain ignorant of -the value of our own powers; and thofe faculties, by which we are qualified to furvey the vast fabric of the world, to contemplate the whole face of nature, to inveftigate the caufes of things, and to arrive at the moft important conclufions as to our welfare and happinefs, remain buried in darkness and obfcurity. No branch of fcience therefore affords us a fairer profpect of improvement, than that which relates to the understanding, defines its powers, and fhows the method, by which it acquires the ftock of its ideas, and accumulates general knowledge:-this is the province of Logic.

It is properly divided into four parts, viz.

I. PERCEPTION. II. JUDGMENT. SONING. IV. METHOD..

III. REA

In this divifion the logicians have followed the course of nature, as we fhall find, if we reflect upon the conduct and progrefs of the understanding. Thefe divifions have fo clofe a connexion with each other, that it is fcarcely poffible to arrive at perfection in one of them, without the affiftance of the

others.

others. To treat of perception we muft inake use of method; and in order to reafon we must form every propofition with a due regard to rules.

1. PERCEPTION confifts in the attention of the understanding to the objects acting upon it, whereby it becomes fenfible of the impreffions they make; and the notices of thefe impreffions, as they exist in the mind, are diftinguished by the name of ideas. If we attend carefully to our thoughts, we shall obferve two fountains or fources of knowledge, from which the understanding is fupplied with all its ideas, or materials of thinking.-Thefe are Senfation and Reflection.

Senfation is the fource of our original ideas, and comprehends the notices conveyed into the mind by impulfes or impreffions made upon the organs of fenfe. Such are the perceptions of colours, founds, taftes, &c. But we derive all thefe ideas, great as · is their number, folely from external objects. Another fource of impreffions arifes from the attention of the mind to its own perceptions, and confiders the various modes, in which it employs itself concerning them. Thus we acquire the ideas of thinking, doubting, believing, &c. which are the different intellectual operations reprefented to us by our own confcioufnefs. This act of the mind is called Reflection; and it evidently implies fenfation, as the impreffions it furnishes proceed from the powers of the understanding occupied in the

contemplation of ideas, with which it has been previously stored.

A proper confideration of these two fources of our thoughts will give us a clear and diftinct view of the nature of the mind, and the firft fteps it' takes in the path of knowledge. From thefe fimple beginnings all our difcoveries derive their origin; for the mind thus ftored with its original notices of things, has a power of combining, modifying, and placing them in an infinite variety of lights, by which means it is enabled to multiply the objects of its perception, and finds itself poffeffed of an inexhauftible ftock of materials for reflection and reafoning. It is in the various comparifons of thefe ideas, according to fuch combinations as are beft adapted to its ends, that we exert ourselves in the acts of judging and reafoning, enlarge our mental profpects, and can extend them in every direction. Thus are we enabled to form a notion of the whole progrefs of the foul, from the first dawnings of thought to the utmoft limits of human knowledge. And it is particularly to be obferved, that among our numerous difcoveries, and the infinite variety of our conceptions, we are unable to find one original idea, which is not derived from fenfation or reflection; or one complex idea, which is not compofed of thefe original ones. “Our obfervation employed either about external fenfible objects, or about the internal operations of our minds, perceived and reflected on by ourselves, is that which fupplics our underftandings with all

the

the materials of thinking. Thefe two are the fountains of knowledge, from whence all the ideas we have, or can naturally have, do fpring.

And,

The ideas, with which the mind is thus furnished, fall naturally under two heads. First, thofe original impreffions which are conveyed by fenfation and reflection, and which exift uniformly and without any fhadow of variety, and are called fimple ideas, fuch as the ideas of colour, found, heat, &c. fecondly, thofe notions which refult from the various combinations of fimple ideas, whether they are fuppofed to co-exift in any particular fubject, or are united together by the mind when it enlarges its conceptions. Thefe are called complex ideas, fuch as a triangle, a fquare, &c. and are of two principal kinds; firft, fuch as are derived from external objects, and reprefent thofe combinations of thought, which have a real existence in nature; of this kind are all our ideas of fubftances. Secondly, the conceptions formed by the mind itself, arbitrarily uniting and putting together its ideas. This makes by far the largeft clafs, and comprehends all thofe ideas, which may be properly termed our own. They are called abftract, or univerfal, fuch as whiteness, beauty, melody, &c. and are produced in various ways; for either the mind conbines feveral fimple ideas together, in order to form them into one conception, in which the number and quality of the ideas united are principally

• Locke, book ii. chap. 1. fee likewise book i. chap. 2. and book ii. chap. 1.

E 3

confidered,

confidered, and thus we acquire all our compound notions; or it fixes upon any of our ideas, whether fimple or compound; or upon the ideas of fubstances, and omitting the circumftances of time, place, real existence, or whatever renders it particular, confiders the appearance alone, and makes that a representation of all that are of the fame kind; or, laftly, it compares things with one another, examines their mutual connexions, and thereby furnishes itself with a new stock of notions, known by the name of Relations, which are proportional, as equal, more, lefs, &c, or natural, as father, mother, &c. or civil, as King and people, general and army, &c. &c. This division of our ideas, as it seems to be the most natural, and truly to represent the manner in which they are introduced into the mind, will be found to include them in all their varieties.

We know that our thoughts, although fo numerous and manifold, are all contained within our own breafts, and are invisible. But as the fupreme Being formed mankind for fociety, he has provided us with organs proper for framing articulate founds, and given us alfo a capacity of using thofe founds as figns of internal conceptions. From hence are derived words and languages. For any found being once determined upon to ftand as the fign of an idea, cuftom by degrees establishes fuch a connexion between them, that the appearance of the idea in the understanding always brings to our re

See Locke on the Ends of Language, book iii. c. 10.

membrance