every direction. Thus are we enabled to form a notion of the whole progress of the soul, from the first dawnings of thought to the utmost limits of human knowledge. And it is particularly to be observed, that among our numerous discoveries, and the infinite variety of our conceptions, we are unable to find one original idea, which is not derived from sensation or reflection; or one complex idea, which is not com posed of these original ones. "Our observation employed either about external sensible objects, or about the internal operations of our minds, perceived and reflected on by ourselves, is that which supplies our understandings with all the materials of thinking. These two are the fountains of knowledge, from whence all the ideas we have, or can naturally have, do spring." Locke, book ii, chap. 1. see likewise book i, chap. 2. and book ii, chap. 1.

The ideas, with which the mind is thus furnished, fall naturally under two heads. First, those original impressions which are conveyed by sensation and reflection, and which exist uniformly and without any shadow of variety, and are called simple ideas, such as the ideas of colour, sound, heat, &c. And, secondly, those notions which result from the various combinations of simple ideas, whether they are supposed to co-exist in any particular subject, or are united together by the mind when it enlarges its conceptions. These are called complex ideas, such as a triangle, a square, &c. and are of two principal kinds; first, such as are derived from external objects, and represent those combinations of thought, which have a real existence in nature; of this kind are all our ideas of substances. Secondly, the conceptions formed by the mind itself, arbitrarily uniting and putting together its ideas. This

makes by far the largest class, and comprehends all those ideas, which may be properly termed our own. They are called abstract or universal, such as whiteness, beauty, melody, &c. and are produced in various ways; for either the mind combines several simple ideas together, in order to form them into one conception, in which the number and quality of the ideas united are principally considered, and thus we acquire all our compound notions; or it fixes upon any of our ideas whether simple or compound; or upon the ideas of substances, and omitting the circumstances of time, place, real existence, or whatever renders it particular, considers the appearance alone, and makes that a representation of all that are of the same kind; or, lastly, 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, less, &c. or natural, as father, mother, &c. or civil, as king and people, general and army, &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 so numerous and manifold, are all contained within our own breasts, and are invisible. But as the Supreme Being formed mankind for society, he has provided us with organs proper for framing articulate sounds, and given us also a capacity of using those sounds, as signs of internal conceptions. From hence are derived words and languages. See Locke on the Ends of Language, book iii, c. 10. For any sound being once determined upon to stand as the sign of an idea, custom by degrees

establishes such a connexion between them, that the appearance of the idea in the understanding always brings to our remembrance the name, by which it is expressed and in like manner the hearing of the name never fails to excite the idea which it is intended to denote.

Definition is the unfolding some conception of the mind by words, which answer to the term made use of as the sign of the conception, " or it is the showing the meaning of one word by several other not synonymous terms." Locke, vol. i, p. 455. It furnishes us with the fittest means of communicating our thoughts; for if we were unable to impart our complex ideas to each other by the aid of definition, it would in many cases be impossible to make them known. This is evident in those ideas which are solely the offspring of the mind. For as they exist only in the understanding, and have no real objects in nature, in conformity to which they are framed, if we could not communicate them to others by description, they must be confined to the narrow limits of a single mind. All the beautiful scenes which spring from the fancy of a poet, and by his lively imagery give such entertainment to his readers, if he was destitute of this faculty of displaying them by words, could not extend their influence beyond his own breast, or give pleasure to any one, except the original inventor.

In our remarks upon language in general, we have adverted to the use and importance of definitions. Locke, book iii, chap. 4. To simple ideas we know them to be inapplicable: but as they are intended to make known the meaning of words, standing for all complex ideas, if we were always careful to form those

ideas with exactness, and to copy our definitions from them with precision, as a skilful painter does a good likeness; much of the obscurity and confusion of language, as it is used both in writing and conversation, might be prevented.

II. The mind being furnished with ideas, the next step necessary in the progress of knowledge is to compare them together, in order to judge of their. agreement or disagreement. In this connected view of our ideas, if the relation is such as to be immediately discoverable by the bare inspection of the mind, the judgments thence obtained are called intuitive, from a word that denotes to look at, or into: for in this case a mere attention to ideas compared is sufficient to inform us how far they are connected or disjoined. Thus, "that the whole is greater than any of its parts" is an intuitive judgment, nothing more being required to convince us of its truth, than an attention to the ideas of whole and part. Intuition therefore is no more than an immediate perception of the agreement or disagreement of any two ideas. This is the first of the three foundations of our knowledge, upon which depends that species of reasoning, which is called demonstration. For whatever is deduced from our intuitive perceptions by a clear and connected series of proofs is said to be demonstrated, and produces absolute certainty. Hence the knowledge obtained in this manner is what we properly term SCIENCE, because in every step of the argument it carries its own evidence with it, and leaves no room for doubt. It is to demonstration that mathematical studies are indebted for their peculiar clearness and certainty.

The second ground of human judgment, from which we infer the existence of the objects which surround us, and fall under the immediate notice of our senses, is experience. When we behold the sun, or direct our eyes to a building, we not only have ideas of those objects, but ascribe to them a real existence independent of the mind. It is likewise by the information of the senses, that we judge of the qualities of bodies; as when we assert that snow is white, fire is hot, or steel hard. As intuition is the foundation of all scientific, so is experience the foundation of all natural knowledge. For the latter being wholly conversant with objects of sense, or with those bodies which constitute the natural world, and we can only discover their properties by a series of observations, it is evident, that in order to improve this branch of knowledge, we must have recourse to the method of trial and experiment.

The third ground of judgment is testimony. There are many facts, that will not admit an appeal to the senses. All human actions, when considered as already past, are of this description. As from the other two grounds are deduced scientific and natural knowledge, so from this we derive historical, by which is meant not only a knowledge of the civil transactions of states and kingdoms, but of all cases where the evidence of witnesses is the ground of our belief.

The act of assembling our ideas together, and joining or disuniting them according to the result of our perceptions, is called judgment; but when these judgments are expressed by words, they are called propositions. A proposition therefore is a sentence denoting some judgment, whereby two or more ideas are affirmed to agree or disagree. The idea of which