1 sources. i. From the Topics whence they are taken. ii. From the Data to which they are addressed. iii. From the Forms of development. Our practical distinctions must be continued by a statement in detail of the divisions and subdivisions under each of these heads. PRACTICAL DISTINCTIONS CONTINUED: (i.) NAMES OF ArguMENTS FROM THE TOPICS WHENCE THEY ARE TAKEN. * 1. External Arguments-Experiment and Testimony. 12. If the argument or proof which we seek under a general head or topic, is not already a part of our knowledge, such general head or topic will be either EXPERIMENT or TESTIMONY; and the argument will be derived externally. It will not, in this case belong to deductive logic, but inductive : that is to say, it will be knowledge yet to be sought and made our own, either by actual experience, or by admitting the experience of others in place of actual experience. Now all our knowledge is originally suggested by external things, and therefore differs not, in its beginning, from that belonging to the topics here proposed under the two names Experiment and Testimony. But the reason for the distinction is this; the arguments sought after under the heads called internal, are presumed to be included in the subjects which we undertake to develop; because to understand the term designating the subject, is to have the knowledge which that understanding necessarily includes. Thus, for instance, to understand what is meant by a plant, a mineral, an animal, is to know what is a plant, what is a mineral, what is an animal: to understand what is meant by pride, or by virtue, is to know what constitutes pride, what constitutes virtue. But the knowledge here supposed is ordinary knowledge; not the recondite relations which the scientific experimentalist reaches; relations which, as to a plant, a mineral, an animal, form the physical sciences, Botany, Geology, Zoology; any treatise or development of which, must be founded on proofs called experimental. Thus, again, if knowledge is proposed to be *The Data and Topics of arguments are quite as necessary to be considered in Rhetoric, as in Deductive Logic; and they are accordingly exhibited, with appropriate differences of view, in the Manual of Rhetoric. developed from the proper names John or Socrates, all we can presume the names to include, is, that there is, or was, a man called John or Socrates:* if more than this is developed, or sought to be developed, it must be, from the peculiar knowledge which the thinker enjoys, the fruit of his peculiar experience, or of the information he derives, as a learned man, from the stores of history. The scientific knowledge thus induced under the term, is not necessarily included in it till the induction takes place; and even then, the arguments are fitted to convince only those who have the knowledge, and not the generality of persons, who use and understand the terms no further than in their ordinary sense. Deductive logic is, however, the art of developing in words such knowledge as we have; and therefore if the thinker has the knowledge here assigned to the two heads called external, the knowledge is, to him, internal, and the distinction a name without a difference; though, as a name, it will be useful, when we have to employ logic as a basis for rhetoric. *Hence Mr. John S. Mill denominates a proper name a non-connotative word. Connotative, according to him, is that which notes something, and, along with it, something more, or, in addition. Thus the word man is connotative; for while it notes any one man, it notes his kind, or all that constitutes him a man. Thus again the word white is connotative; for while it notes the quality, white, in any one thing, it notes or implies it in all other white things. On the other hand, John and whiteness are said to be non-connotative; and we may perhaps exemplify the reason given for this by saying, that they are words incapable of being used in predication otherwise than specially: we cannot say, for instance, "This man is John" by virtue of any general knowledge included in the word, but only by virtue of our special accidental knowledge that such is his name: neither can we say of anything, except of whiteness itself, that "It is whiteness;" for the word whiteness is so grammatically conditioned as to be immediately applicable only to our knowledge of what whiteness is, and not immediately to the white things from which that knowledge has been derived. In thus explaining the distinction sought to be enforced by the term non-connotative, we wish it to be seen that it arises entirely out of the Aristotelian doctrine of predication: and its utility or inutility must be estimated by the utility or inutility of that doctrine. Whether, with just views of the relation which language bears to thought, John and whiteness are not connotative, as well as man and white, we leave our student to inquire. 2. Internal Arguments-Definition, Etymology, Enumeration, (not Induction,) Genus and Species, Cause, namely, Efficient or A-priori, and Final or A-priori, Effect or A-posteriori; Antecedents, Consequents, Adjuncts; Comparison, namely, Similitude, Analogy or Parity of case, Contraries, Proportion, and A-fortiori. 13. When, having laid down some point or purpose of development, we go on to argue the truth of what we assert by appealing to the nature of our subject, as it is, or as it might be exhibited in a definition, we are said to reason from DEFINITION. If, for instance, we desire to develop the knowledge contained in the proposition, Man is accountable for his actions, the argument may be, that he is a creature endowed with reason and liberty; which is a definition of man's nature. This is an argument by virtue of the datum, that every creature endowed with reason and liberty is accountable for his actions; and both being admitted as a part of our previous knowledge, the conclusion is inevitable. Or if we desire to place the truth evidently before us in words, that certain lines are equal to one another, the argument may be, that they are radii of the same circle. This is an argument by virtue of the datum, that the radii of the same circle are always equal; and both being admitted as belonging to our previous knowledge, the conclusion is again inevitable. 14. When we develop our knowledge from the original sense of the word that stands for our knowledge, we are said to reason from ETYMOLOGY. If, for instance, we desire to develop the knowledge, That the idle have no relaxation,the argument may be, that the word relaxation originally signifies, the loosening of what is tight. Borrowing_from another topic hereafter mentioned, namely, Analogy or Parity of case, we add to the argument from Etymology, the further argument, That as the idle never apply, or draw their faculties tight, so they can never be said to relax their faculties. The former is an argument by virtue of the datum, that the idle do not loosen what is Tight; and the latter an argument by virtue of the datum, that Not to draw the faculties tight and not to apply them, are expressions that mean the same thing. All this being admitted as a part of previous knowledge, the conclusion is inevitable. 15. When we develop the knowledge we entertain under a general term, or a general proposition, by detailing the particulars which constitute our knowledge, we are said to reason from ENUMERATION. Thus, for instance, we develop our knowledge of what a dozen means, or a score, by counting up to a dozen, or a score inclusively. This is an argument by virtue of the datum that the number so counted is a dozen, or a score; and the conclusion follows inevitably. Thus, again, if we wish to develop the knowledge contained in the proposition, A fine art always addresses, as its appropriate object, our imaginative sensibility, through the sense of hearing or of sight; our first argument may be an enumeration of the fine arts, namely, Poetry, Music, Painting, Sculpture, accompanied, in each instance, by the more special proposition that Poetry addresses, as its appropriate object, our imaginative sensibility, through the sense of hearing; Music addresses, &c., through the sense of hearing; Painting addresses, &c., through the sense of sight; Sculpture addresses, &c., through the sense of sight. This enumeration is an argument by virtue of the datum, that Poetry, Music, Painting, Sculpture are all the fine arts; and both being admitted as a part of our previous knowledge, the conclusion is inevitable. Thus, again, if we wish to develop our knowledge, that a heavy body lifted from the earth, has always fallen to the earth again when the sustaining power was removed, our argument may be, the enumeration of A, B, C, D, &c., which in our own experience or that of others, has, in each instance, fallen to the earth under the circumstances stated. This again, is an argument by virtue of the datum, that A, B, C, D, &c., are all the things, or represent all the things, on which the experiment has been tried; and both being admitted as a part of our previous knowledge, again the conclusion is inevitable. The argument from Enumeration is sometimes confounded with the argument from Induction but Induction as we have seen, is not an internal argument; and the conclusion it suggests is not included in the premises, and therefore is not a necessary conclusion but an inference, although we do not the less receive it as true. Thus, for instance, having to ascertain whether it is a truth or general law, that every heavy body being lifted from the earth, will fall again to it if every intervening thing be removed, we have recourse to experiment; and the experiment answering our expectation, we then infer that as A, B, C, D, &c., have fallen again to the earth after having been lifted from it, so all bodies whatever will fall to earth under the same circumstances, in other words, that this is a general property of bodies near the earth's surface. Now, the inference here is not included in the premises; the necessary conclusion from which, is, that A has fallen, that B has fallen, &c., not that Z, Y, X, &c., will fall. And this sort of conclusion is called the Inference of Physics. Yet the difference between the argument from Enumeration and Induction is done away with by conceding the knowledge, a knowledge which all people must acquire,*— that * But why must they acquire it? The philosophers of the Scottish school here come in with what they call a fundamental principle of belief. I am glad to avail myself of the objections to that dogma, which one of their number, Mr. James Douglas of Cavers, thus urges : "That Reid, Stewart, and Turgot, have been mistaken, in proposing such an original law of thought, as a belief in the continuance of the laws of nature, will easily appear. That can never be an original proposition which consists of slowly acquired terms. Had we an innate idea of nature, of laws, or of permanence, then we might have such an ultimate and instinctive principle: but since the notion of nature is very gradually acquired, and since the term laws is metaphorical, the absurdity of our forming a conclusion while we are yet unfurnished with the premises, will be abundantly apparent. Should it be said that this law of thought remains dormant till we become acquainted with the meaning of nature and of laws, though this supposition is sufficiently absurd in itself, it may be further observed, that our belief of this permanence of the laws of nature, is certain and uniform : but no certain conclusion can be attached to variable terms, such as the very complex and fluctuating notions of nature and her laws. Unless we had within us a model of what nature is, and what her laws are, and also whether continuance is to be understood in an absolute, or in a qualified sense, it would be impossible to arrive with any certainty at the conclusion, which is thus made the foundation of our belief, and of reasoning. The truth is, here is a confusion between acquiescence and belief. To acquiesce in the regularity of nature, is one of our earliest habits, but to believe in the permanence of the laws of nature, is one of the ripest acts of the understanding. The process from childhood does not seem to be well understood-the child receives all things, according to the philosophic expression of Wordsworth, in "a wise passiveness.' It has no doubts, and therefore can have no belief. The permanence of the laws of nature mould the thoughts of the child to their own continual recurrence: what is still more, the structure of his own frame corresponds and fits in with the laws of external nature. Not only are all his thoughts moulded, for example, to the succession of day and night, but the structure both of his |