ous use of terms which cannot be too rigidly confined to a single application, is a prevailing feature of Prof. T.'s style; and forms its worst defect. Considered simply as a blemish of style, it is amply compensated by the general simplicity, and the occasional force and even beauty of the language: but viewed as a defect in the vehicle of abstruse philosophical speculations, it does not admit of compensation.

In the commencement of his discussion, Prof. T. refers all psychological truths to certain " primary conceptions," which are plainly revealed in our consciousness, and which "are necessary to account for, explain, and define, all our other knowledge." He then endeavors to ascertain the marks by which we distinguish them. Of these marks or tests, he has specified three:

L. They are irresistibly affirmed by the understanding; II. They are incapable of definition, explanation or proof; III. They form the basis of knowledge and conclusions. When it is considered that these "first truths," as our author terms them, are to determine all other questions in both mental and moral science,-are to explain and account for all our knowledge, it certainly seems highly desirable that they should themselves be ascertained with the utmost accuracy, and expressed with the utmost precision. We are by no means sure, however, that Prof. T. has carried his analysis of this part of his subject to its furthest limit; indeed, we consider additional discrimination not only practicable, but essential to a successful discussion of the topic of which he treats. In the statement, for instance, of the second of these tests, the words indefinable, inexplicable, and indemonstrable, are employed as descriptive of the same quality of a first truth— "it is this very quality of inexplicableness, or of indefinableness, or indemonstrableness, which makes it a first truth." (Vol. II. p. 20.) Now it is evident enough that a first truth cannot be a truth which may be drawn by logical inference from any other; if it could, it were not a first truth. But it is difficult to perceive why a first truth may not be defined, as well as any other truth. The only idea which can be con

veyed by the term define, as applied to a truth, is the enumerating of its various elements; and this surely may be done for a first truth as well as for any other. A truth always contains certain elements. It is an affirmation of the agreement or disagreement of certain ideas; and when these ideas, and the facts predicated of them, are all specified, as they may certainly be, that truth is "defined" in the only sense in which any truth can be. For example :—it is a first truth that every perceived change implies a cause. This truth contains, as every truth must, its subject, its predicate, and its copula ; and when these are all specified, the truth is perfectly defined. The idea expressed by the word cause, may be incapable of definition; but the characteristic of this idea is not necessarily a characteristic of the truth which contains it: the truth itself is no more incapable of definition because it has the conception of cause for one of its elements, than the truth that the will is a cause, is indefinable for the same reason.

It would seem, therefore, that the language in which this test is expressed, implies two distinct things. The quality of indemonstrableness applies to a truth properly so called; it implies the existence of subject and predicate; and declares that their agreement or disagreement is not capable of demonstration. The quality of indefinableness, on the other hand, is inconsistent with the idea of a truth, but refers to a single element of a truth, and declares that this is simple or incapable of being separated into parts. The one refers to first truths; the other to elementary, or uncompounded, or as we prefer to term them, simple ideas.

Our author proceeds next to apply these tests to some of the ideas which are to be prominent in the subsequent discussion; and arrives at the conclusion that time, space, cause, and substance, are first truths. If, however, we apply our foregoing observations to any one of these truths, the necessity of some closer discrimination becomes at once apparent. Cause, says Prof. T., is a first truth. But what, we ask, is true of cause? That it has actual existence, or that it has not? that it is a substance, or that it is not? That it is a

mere uniform antecedent, or that it is not? Plainly, nothing is yet predicated of it; the word stands simply as the mark of a certain conception of the author's mind, of which he has not yet affirmed even that the thing denoted by it has any real existence. The declaration that this idea does, or does not, correspond with reality-that it agrees, or disagrees, with some other idea, must be made before we have any thing which can properly be termed a truth, before we have any thing to which the terms demonstrable or indemonstrable can with propriety be applied.

Setting aside, however, all considerations of this nature, we will examine Prof. T.'s application of his criteria to some of the more important of these conceptions.

Substance is a first truth in the scheme of our author. He tests it by the marks above related, as follows: 1. "It is a positive affirmation of the intelligence; 2. Substance cannot be defined or demonstrated; 3. It is the basis of certain knowledges and conclusions." Prof. T. in his remarks upon the application of the second of these tests, says, (Vol. II. p. 23,) "It cannot be logically defined because it does not admit of distribution into genera."—" Nor can it be metaphysically defined, because there are no metaphysical essences and properties beyond that expressed by the simple word substance." It is here implied that the word substance denotes some one idea which cannot be analyzed-cannot be separated into constituent eleWe regret that our author has not furnished some means of identifying this solitary conception. He might by some periphrasis, or some illustrations, have shown his readers. what he takes this indefinable something to be; as it is, they are left without the means of judging of the correctness of his conception of it.

ments.

In opposition to this view, we cannot but consider it possible to define this idea, and thereby to furnish the most complete refutation of the indefinableness claimed for it. The term denotes, we conceive, a necessary, but by no means a simple idea. It is to be defined by specifying its elements;

which we do as follows: It is a thing which possesses real existence-essential existence-and properties. First, it possesses real existence. This statement implies a division of our conceptions into two classes, those which do, and those which do not, possess reality; and affirms that the idea of reality is an element included in the term we are defining: a mathematical point would be of the latter class. Next, it possesses essential existence. We here indicate a classification of real existences-dividing them into those which exist independently, i. e. exist by themselves, and those which exist as modifications of other things, upon which other things their existence is seen to be necessarily dependant, as motion, utility, form, sound, etc. Substance includes the former of these ideas; it is a thing which exists not as a modification of something else, but essentially; if our readers will bear a term so scholastic, it is an entity.

Lastly, it sustains properties. Whether any such thing as we have called an essence, or entity, can exist without properties, might perhaps be a question; but whether it can or not, the word substance contemplates it only as standing in this relation. The etymology of the term indicates this idea. -it is that which is the basis of those properties or qualities. by which alone we know things.

We have thus designated three distinct and intelligible ideas, as included in the conceptions of substance: it only remains to show that they are all essential to it. Of this our readers may easily satisfy themselves, by attempting to form the conception without including them. If it should be found impossible, as we believe it will, to conceive of a substance which does not possess real existence-essential existenceand properties, it must be admitted that the term substance is defined. It is a convenient term for the designation of a certain combination of ideas; ideas which, it is true, are of the most general character; but such must the ideas be, which define any very abstract expression.

The same course of remark applies to the word cause. This also is claimed as a first truth, and pronounced indefina

ble. Prof. T. says, (Vol. II. p. 32,) "Is there any primary conception or idea of the reason to which it can be referred as comprehending it? There is none unless it be substance. or spirit. Shall we say of cause, it is substance? Then we run counter to a primary and necessary conception, because we conceive of cause as residing and acting in substance, and not as substance itself."

The position here taken that "we run counter to a necessary conception," if we refer the idea of cause to that of substance as a more general one, rests upon the following reasoning extracted from p. 25. "Cause indeed exists in physical masses, which are divisible, and may be described by an enumeration of their parts and qualities; but cause may not be confounded with the masses themselves. I appeal to the consciousness of every man, whether the cause of combustion is the same as the physical substance consumed, or dissolved into its elements? No, every one replies; fire is not wood. But is the fire some other body which, coming into juxtaposi tion with wood, consumes it? By no means." Another example upon the same page illustrates the same point:"Again, is the flowing torrent, and the gravitation which is taken as the cause of its flowing, the same?"

As our limits forbid us to follow Prof. T. minutely through these illustrations, we must content ourselves with a more general objection against the mode of reasoning here adopted. It is attempting to prove a universal negative from a particular negative. The facts that wood is not the cause of its own combustion, and that water is not the cause of its own motion, no more prove that substances are not causes, than the fact that the moon is not the cause of madness, proves it. Surely it does not follow from the fact that a certain substance is not the cause of a certain effect, that no substance is a cause. Yet these illustrations constitute the sum of the argument, by which our author would show that substances are not causes.

After this endeavor to prove that cause cannot be defined by substance, the next step is to argue that it cannot be defined at all. Several kinds of definitions are mentioned, under the