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paths that have been traversed by others, or to strike out into the most devious extravagances: the greater part of the world will either totally renounce their reason, or reason only from the wild suggestions of an heated imagination.
“ From the same source may be derived those divisions and animosities which break the union both of public and private societies, and turn the peace and harmony of human intercourse into dissonance and contention; for while men judge and act by such measures as have not been proved by the standard of dispassionate reason, they must equally be mistaken in their estimates both of their own conduct and that of others.”
The second operation of the mind is judging, by which it discovers the agreement or disagreement of any two . ideas which it may have occasion to compare. Thus, for instance, having in my mind an image of the sun, and an idea of roundness, I compare, or bring both together, and discover their fitness. I then affirm, or say to myself, the sun is round; and the words, in which I express that affirmation, form a sentence, called by logicians, a proposition. If, upon comparing two ideas, I perceive their disagreement, as that the sun is not a square, nor a dark, nor a cold body, the sentence, which I then make use of, is called a negative proposition.
Every proposition, whether affirmative or negative, contains at least two ideas, besides the assertion of their agreement or disagreement. The first idea, be it simple or complex, is that of which something is affirmed or denied, and is called the subject of the proposition ; the second idea is the property, or quality, or attribute, which
is either affirmed or denied to belong to, or to agree with, the first idea, and is called the predicate of the proposition: the word expressive of the affirmation or denial is called the copula, or connective of the proposition.
When the two ideas, thus linked together, are immediately derived from the external senses, or from our bodily feelings, and are clearly conceived, we can entertain no doubt of the accuracy of our judgment, or of the truth of the proposition, if correctly expressed. We also rely with full confidence on the report of our mental feelings, or consciousness, as well as on our intuitive perception of a great number of what are called self-evident truths. To these we may add a fourth class of propositions, founded on the testimony of others, and on the information they afford respecting persons, places, or things, which we ourselves cannot examine. In many cases, such testimony is unquestionable ; but, in others, the probabilities for and against the veracity or accurate knowledge of the reporter are so equally poised as to leave the mind in a state of suspense.
But from whatever source we derive the two ideas which we propose to compare, and upon the agreement or disagreement of which our judgment is to be exercised, we must take care that the mind, in performing this grand operation, be perfectly free from every thing which may obstruct the full and fair exertion of its powers, unbiassed by partiality or prejudice, unseduced by fallacious appearances in things, ambiguities in words, or any disposition to deceive or be deceived.
Mr. BARRON, from whose Lectures on Logic some of these hints are taken, lays down the following three rules to direct our practice in forming just and useful judgments, and thereby preparing the best materials for the farther exercise of our reason, and for the increase or enlargement of our knowledge.
I. “ Beware of precipitation, and never decide concerning the truth or falsehood of any proposition, till you well consider whether the words accurately express the ideas, whether you have distinct conceptions of the ideas, whether your minds are divested of prejudices, and whether you have fully canvassed the evidence.
II. “ If, after employing every precaution, you still find information incomplete, or ideas not sufficiently clear, suspend your judgment till farther investigation or greater experience shall qualify you to decide.
III. « Be satisfied with the evidence which the nature of a proposition admits."
For a complete illustration of these rules, I feel a pleasure in referring to the Lectures themselves, which will be found of great service to the young logician, and prepare him to read LoCKE, as before recommended, with the utmost advantage, and without any danger of being allured too far into the region of metaphysics.
This is the third and last operation of the mind in the discovery of truth and knowledge, and it takes place when the agreement or disagreement of any two ideas does not immediately appear either upon intuition, or from the evidence of our bodily or mental feelings. In these cases, our judgment is suspended till we can find out some intermediate idea or train of ideas, bearing such a relation to each of the ideas to be compared as may enable us to decide on the truth or falsehood of what is affirmed or denied of them; and the process, by which we attain to this knowledge, is called reasoning. Thus, to prove that we should love virtue, or in order to be satisfied of the truth of the proposition, that virtue is amiable, I employ an intermediate idea, that of happiness, and if I find, upon comparing it with each of the two former, virtue and love, that they separately agree with it, I conclude that they agree with one another, and I reason thus :
We should love what makes us happy ;
This is what is termed a syllogism in regular form, consisting of three propositions, the first called the major, the second the minor, and the third the conclusion. But though all the old books of logic are filled with little more than figures, and forms, and pretended illustrations, but real confusions of this syllogistic mode of reasoning, we readily perceive that the mode itself is easy, and unerring, if we advance by regular and careful steps from the agreement or disagreement of two ideas, which we know, to that of any third idea, which may not be so obvious, yet capable of being compared with each of them, and of thus being made, as it were, an intermediate link in the chain. The length of the chain, or the number of links, if properly connected, can make no difference; and the demonstration that the three angles of a triangle are equal to two right angles, though requiring more details of proof, or more comparisons, is not ultimately less convincing than that the sum of three, four, and five, is equal to that of two sixes.
In reasoning, therefore, or in forming just arguments, and drawing proper conclusions, we have nothing more to do than to observe the caution already recommended in the exercise of our judgment, in comparing the ideas contained in each separate proposition, and then satisfying ourselves that the last inference is the just and necessary result of the agreement or disagreement discovered in those several comparisons. The manner, in which the mind proceeds through ever so long a train of intermediate ideas, without any doubt or perplexity, is thus pointed out by Mr. BARRON:
“ It must compare the first idea of the proposition with the first intermediate idea, and pass a judgment on their agreement or disagreement. It must next compare the first intermediate idea with the second intermediate idea, and pass a similar judgment. It must proceed, in like manner, through all the intermediate ideas, and pass similar judgments, till it comes to compare the last intermediate idea with the latter idea of the proposition; and from all these intermediate judgments the conclusive judgment is deduced, concerning the agreement or disagreement of the two primary ideas of the proposi
I am happily relieved from the necessity of entering into any details on the use or abuse of syllogisms, or on the means of guarding against fallacy in our own reasonings, and of detecting the fallacy or sophistry of others, as all these matters are very minutely discussed in the Lectures now quoted, and before recommended. It remains only for me to explain, what was not connected with the author's design in that work, the difference between logical and oratorical arguments.
Zeno, the famous founder of the sect of the Stoics, used to compare the logical argument to a clenched fist, and the oratorical argument to an open
saying is more remarkable for the whimsicality of the comparison than for its truth. The syllogistic mode of reasoning is not more convincing and persuasive than the oratorical, and does not more effectually reduce our adversaries or opponents to the possibility of a reply. The Logician draws up his argument in regular form, his major, his minor, and his conclusion: the Orator lays aside all that formal stiffness; and, by inverting the order of the propositions, by frequently omitting one or other of them which may be easibly supplied by the hearer, and by con