no imperfection in them, if he always use the same sign. for the same idea.

2. Communication of words has also a double use, civil and philosophical. By their civil use, I mean such a communication of ideas as may serve for the ordinary affairs and conveniences of life. By their philosophical use, I mean such as may convey precise notions of things, and express satisfactorily general propositions. These uses are very distinct; less exactness being required in the one than in the other.

The chief end of language being to be understood, words serve not to that end when they do not excite in the hearer the same idea that they stand for in the mind of the speaker. Now since sounds have no natural connexion with our ideas, the uncertainty of their signification has its cause in the ideas they stand for; and therefore the idea which each sound stands for must be learned and retained by those who would discourse intelligibly. But this is hardest to be done, 1. where the ideas they stand for are very complex ; 2. where the ideas they stand for have no certain connexion in nature, and no standard to adjust them by ; 3. where the signification of the word is referred to a standard not easy to be known; 4. where the signification of the word, and the essence of the thing, are not exactly the same.

The names of mixed modes are liable to great obscurity 1. Because of that great composition these complex ideas are often made up of. When a word stands for a very complex idea, it is not easy for men to form and retain that idea, so as to make the name stand for the same precise idea without variation. Hence names of compound ideas, such as moral words, have seldom, in two different men, the same precise signification. 2. Because the names of mixed modes want standards in nature. They are assemblages of ideas put together at the pleasure of the mind, not to copy any thing really existing, but to

rank things as they agree with the archetypes the mind has made. What the words murder, sacrilege, &c. signify, can never be known from the things themselves. Many parts of these complex ideas are not visible in the actions themselves: the intention of the mind, or the relation of holy things, has no necessary connexion with the outward action of him who commits either. They have their combination only from the understanding, which unites them under one name. Common use, that is the rule of propriety, may be supposed to settle the signification of language, and it does for the purposes of common conversation; but common use is not sufficient to adjust them to philosophical discourses; there being scarcely any name of any very complex idea, which may not be made the sign of far different ideas. From which it is evident that the names of such ideas are liable to be of doubtful signification. Though the names glory and gratitude be the same in every man's mouth, yet the complex ideas which every one intends by those names, are different in men using the same language.

The way also in which the names of mixed modes are learned, contributes to the doubtfulness of their signification. To make children understand the names of simple ideas and substances, people show them the thing, and then repeat the name. But of mixed modes, especially moral words, the sounds are learned first, and their meaning is left to the explication of others or to their own observation and industry; which being little laid out in the search of the true meaning of names, these moral words, in most men's mouths, are little more than bare sounds. Where shall one find any controversial debate or familiar discourse concerning honor, faith, grace, religion, church, &c. wherein it is not easy to observe the different notions men have of them? And hence we see that in the interpretation of laws, whether divine or human, comments beget comments, and explications make new

matter for explications; and of limiting, distinguishing, varying the signification of these moral words, there is no end.

It is needless to remark what obscurity this has brought on the writings of men who have lived in re mote ages and different countries, since the numerous volumes of learned men employing their thoughts that way are more than enough to show what attention and study are required to find the true meaning of ancient authors. But there being no writings we have any great concernment to be solicitous about, but those which contain truths to be believed or laws to be obeyed, we may be less anxious about the sense of other authors; and if they use not their words with a due clearness and perspicuity, we lay them aside, and resolve with ourselves,

Si non vis intelligi, debes negligi.

If the names of mixed modes are uncertain for want of standards existing in nature, the names of substances are doubtful for a contrary reason; because they are referred to standards made by nature. In these we must suit our complex ideas to real existences. Here we have patterns to follow; but patterns that will make the signification of their names very uncertain; for the names must be of doubtful meaning, if they be referred to standards, that either cannot be known at all, or can be known but imperfectly and uncertainly.

The names of substances have a double reference. 1. They are made to stand for the real constitution of things, from which all their properties flow. But this real constitution being unknown to us, any sound that is put to stand for it must be very uncertain in its application. 2. The simple ideas that are found in substances being that which their names immediately signify, are the proper standards to which their names are referred. But these archetypes still leave the names with uncertain significations; because the sim

ple ideas united in the same subject being numerous, and having all an equal right to go into the complex idea, men frame very different ideas about it, and so the name they use comes to have very different significations. He that shall observe what alterations any one of the baser metals is apt to receive, will not think it strange that I count the properties of bodies not easy to be collected. The complex ideas of substances being made up of such simple ones as are supposed to co-exist in nature, every one has a right to put into his complex idea those qualities he has found to be united together. For though in the substance of gold one satisfies himself with color and weight, yet another thinks solubility in aqua regia as necessary to be joined to it: others put in fusibility, ductility, fixedness, &c. Each has his standard in nature; and what judge shall determine which of them has established the right signification of the word gold? From hence it follows that the complex ideas of substances will be very various, and the signification of their names uncertain. Besides, there is scarcely any thing which does not in some of its simple ideas communicate with a greater, and in others with a less number of particular beings; in which case who is to determine the collection of simple ideas to be signified by the name; or prescribe which obvious qualities are to be left out, or which more secret to be put into the signification? All which produces that doubtful signification in the names of substances, which causes uncertainty and disputes when we come to a philosophical use of them.

In common conversation, general names of substances, regulated by some obvious qualities, well enough design the things men would be understood to speak of; but in philosophical inquiries, where general truths are to be established, there the precise signification of the names of substances will be found not only not to be well established, but hard to be so. I was once at a meeting of physicians, when there arose a question

nerves.

whether any liquor passed through the filaments of the The debate having been managed by a variety of arguments on both sides, I requested, that before they proceeded farther, they would first establish what the word liquor signified. They were at first surprised at the proposal, but on examination found that the signification of the word was not so settled as they imagined. This made them perceive that their dispute was about the signification of that term, and that they differed very little in their opinion concerning some subtle matter passing through the nerves, though it was not so easy to agree whether it was to be called liquor or no.

From what has been said, it is easy to observe that the names of simple ideas are least liable to mistakes ; 1. because the ideas they stand for, being but one single perception, are more easily retained than the more complex ones; and, 2. because they are never referred to any other essence, but barely that perception they immediately signify. White, sweet, yellow, bitter, carry a very obvious meaning with them; but what precise collection of simple ideas, modesty, or frugality, stands for in another's use, is not so certainly known; and however we are apt to think we well enough know what is meant by gold or iron, yet the precise complex idea, others make them the signs of, is

not so certain.

By the same rule, the names of simple modes are, next to those of simple ideas, least liable to doubt; and in general the least compounded ideas in every kind have the least dubious names.

The disorder that happens in our names of substances proceeding from our want of knowlege of their real constitutions, it may be wondered why I charge ́this rather on our words than understandings. I must confess, that when I began this discourse, I had not the least thought that any consideration of words was at all necessary to it. But when I began to examine the