interesting application-the abstract principles lead, which are first laid before the student; so that he will often have to work his way patiently through the most laborious part of the system before he can gain any clear idea of the drift and intention of it.

This complaint has often been made by chemical students, who are wearied with descriptions of oxygen, hydrogen, and other invisible elements, before they have any knowledge respecting such bodies as commonly present themselves to the senses. And accordingly some teachers of chemistry obviate in a great degree this objection, by adopting the analytical instead of the synthetical mode of procedure, when they are first introducing the subject to beginners; i. e. instead of synthetically enumerating the elementary substances, proceeding next to the simplest combinations of these,—and concluding with those more complex substances which are of the most common occurrence, they begin by analyzing these last, and resolving them step by step into their simple elements; thus at once presenting the subject in an interesting point of view, and clearly setting forth the object of it. The synthetical form of teaching is indeed sufficiently interesting to one who has made considerable progress in any study; and being more concise, regular, and systematic,

is the form in which our knowledge naturally arranges itself in the mind, and is retained by the memory but the analytical is the more interesting, easy, and natural kind of introduction; as being the form in which the first invention or discovery of any kind of system. must originally have taken place.

It may be advisable, therefore, to begin by giving a slight sketch, in this form, of the logical system, before we enter regularly upon the details of it. The reader will thus be presented with a kind of imaginary history of the course of inquiry by which that system may conceived to have occurred to a philosophical mind.

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BOOK I.

ANALYTICAL OUTLINE OF THE SCIENCE.

§ 1.

In every instance in which we reason, in the strict sense of the word, i. e. make use of arguments, whether for the sake of refuting an adversary, or of conveying instruction, or of satisfying our own minds on any point, whatever may be the subject we are engaged on, a certain process takes place in the mind, which is one and the same in all cases, provided it be correctly conducted.

Of course it cannot be supposed that every one is even conscious of this process in his own mind; much less, is competent to explain the principles on which it proceeds. This indeed is, and cannot but be, the case with every other process respecting which any system has been formed; the practice not only may exist independently of the theory, but must have preceded the theory. There must have been Language before a system of Grammar could be devised; and musical compositions, previous to the science of Music. This, by the way,

will serve to expose the futility of the popular objection against Logic, that men may reason very well who know nothing of it.* The

* Locke has a great deal to this purpose; e. g. in chap. xvii. "on Reason," (which, by the way, he perpetually confounds with Reasoning.) He says, in § 4, "If syllogisms must be taken for the only proper instrument of reason and means of knowledge, it will follow, that before Aristotle there was not one man that did or could know any thing by reason; and that since the invention of syllogisms there is not one in ten thousand that doth. But God has not been so sparing to men to make them barely two-legged creatures, and left it to Aristotle to make them rational, i. e. those few of them that he could get so to examine the grounds of syllogisms, as to see that in above threescore ways that three propositions may be laid together, there are but fourteen wherein one may be sure that the conclusion is right," &c. &c. "God has been more bountiful to mankind than so: He has given them a mind that can reason without being instructed in methods of syllogizing," &c. &c. All this is not at all less absurd than if any one, on being told of the discoveries of modern chemists respecting caloric, and on hearing described the process by which it is conducted through a boiler into the water, which it converts into a gas of sufficient elasticity to overcome the pressure of the atmosphere, &c., should reply, "If all this were so, it would follow that before the time of these chemists no one ever did or could make any liquor boil."

In an ordinary, obscure, and trifling writer, all this confusion of thought and common-place declamation might as well have been left unnoticed; but it is due to the general ability and to the celebrity of such an author as Locke, that errors of this kind should be exposed.

He presently after inserts an encomium upon Aristotle, in which he is equally unfortunate; he praises him for the "invention of syllogisms;" to which he certainly had no

parallel instances adduced, show that such an objection might be applied in many other cases, where its absurdity would be obvious; and that there is no ground for deciding thence, either that the system has no tendency to improve practice, or that even if it had not, it might not still be a dignified and interesting pursuit.

One of the chief impediments to the attainment of a just view of the nature and object of Logic, is the not fully understanding, or not sufficiently keeping in mind, the SAMENESS of the reasoning process in all cases. If, as the ordinary mode of speaking would seem to indicate, mathematical reasoning, and theological, and metaphysical, and political, &c. were essentially different from each other, i. e. different kinds of reasoning, it would follow, that supposing there could be at all any such science as we have described Logic, there must be so many different species, or at least different branches of Logic. And such is perhaps the

more claim than Linnæus to the creation of plants and animals; or Hervey, to the praise of having made the blood circulate; or Lavoisier, to that of having formed the atmosphere we breathe. And the utility of this invention consists, according to him, in the great service done against "those who were not ashamed to deny anything;" a service which never could have been performed, had syllogisms been an invention of Aristotle's; for what sophist could ever have consented to restrict himself to one particular kind of arguments, dictated by his opponent?