1. As the leader of the party, he naturally believes in Democratic principles.
II. AMBIGOUS TERMS. (EQUIVOCATION; CONFUSION OF TERMS.)
The fallacy of ambiguous terms consists of using the same term in two distinct senses in the same argument. Thus if one were to argue that "no designing person ought to be trusted; engravers are by profession designers; therefore they ought not to be trusted," it is quite apparent that the term "design" means totally different things in the two premises. The same fallacy occurs in the argument, "Since the American people believe in a republican form of government, they should vote the Republican ticket." Again:—
"Interference with another man's business is illegal;
"Underselling interferes with another man's business;
"Therefore underselling is illegal."
J. S. Mill in his System of Logic discusses the fallacy of ambiguous terms with great care. In part he says:—
The mercantile public are frequently led into this fallacy by the phrase "scarcity of money." In the language of commerce, "money" has two meanings: currency, or the circulating medium; and capital seeking investment, especially investment on loan. In this last sense, the word is used when the "money market" is spoken of, and when the "value of money" is said to be high or low, the rate of interest being meant. The consequence of this ambiguity is, that as soon as scarcity of money in the latter of these senses begins to be felt,—as soon as there is difficulty of obtaining loans, and the rate of interest is high,—it is concluded that this must arise from causes acting upon the quantity of money in the other and more popular sense; that the circulating medium must have diminished in quantity, or ought to be increased. I am aware that, independently of the double meaning of the term, there are in the facts themselves some peculiarities, giving an apparent support to this error; but the ambiguity of the language stands on the very threshold of the subject, and intercepts all attempts to throw light upon it.
As countless words and expressions have several meanings, there is almost no limit to the confusion which this fallacy can cause. Some of the most common terms that are used ambiguously are right, liberty, law, representative, theory, church, state, student.
By carefully defining all terms that have more than one meaning and by insisting on a rigid adherence to the one meaning wherever the term is used, a debater can easily avoid fallacies of this sort in his own argument and expose those of his opponent.