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O conspiracy,

Sham'st thou to show thy dangerous brow by night,
When evils are most free? O, then, by day

Where wilt thou find a cavern dark enough

To mask thy monstrous visage? Seek none, conspiracy;
Hide it in smiles and affability;

For if thou path, thy native semblance on,
Not Erebus itself were dim enough

To hide thee from prevention.

Act II, Sc. 1.

The posture of your blows are yet unknown;
But for your words, they rob the Hybla bees,
And leave them honeyless.

Logical Definition.

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- Act V, Sc. 1.

107. Another method of connecting the new idea with old ideas is by the process known as definition. To define an idea is to put it in its appropriate place among the classes of things with which we are familiar. This we can do most easily by the following method: (1) we mention some large class with which the reader is already acquainted; then (2) by naming some prominent characteristic of the thing to be defined, we show where, in that large class, it properly belongs. Thus if our purpose is to define the idea hypnotism, we may begin by saying that it is a kind of sleep (sleep being a large class with which we are already familiar), and complete the definition by adding that it is induced by motions of the hand or other suggestions of the operator (this being the essential characteristic which distinguishes this kind from other kinds of sleep). Hypnotism is thus placed definitely among the classes of things with which we are familiar.

The large class is termed the genus. The distinguishing characteristic is termed the differentia. It is generally best to choose as small a genus as can be used conveniently. To define a gnat as an animal is hardly to define at all; the class is too large. It is better to classify it as an insect, and still better as a fly. So in defining a Pastoral we may say that it is a piece of literature treating of rural life. Here the genus, "piece of literature,” is a very large class including both prose and poetry. The definition will be more accurate as well as more helpful if we say that a Pastoral is a narrative or slightly narrative poem. And it will be still further improved if we add the differentia, as above, treating of rural life. The following is a convenient method of displaying and separating the parts of a logical definition:

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As we meet definitions in our text-books, in the dictionaries, and in general reading, we do not always find the parts in the logical order shown above. Thus if we read, "Politics treats of the principles governing the conduct of state affairs; it is a branch of civics," we see that here the differentia comes before the genus, and that the normal order would be, "Politics is that branch of civics, which treats of the principles governing the conduct of state affairs."

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Often, too, a definition is incomplete. The genus may be missing as in this, "A pastoral treats of rural life; or the differentia may be missing as in this, " A monitor is a sort of battleship." Sometimes, for a given purpose, an incomplete definition like those just quoted will serve well enough; but especially in the class room, incomplete definition is a widespread fault which every student should try to overcome in his own practice.

A synonym is useful in definition when it is a more familiar word than the word to be defined. Often, however, even in dictionaries, a synonym that is even less familiar than the word it purports to explain will be given. A person who doesn't know what a "tariff" is will probably not be enlightened if told that it is an "impost" or a "duty." If I do not know what "buncombe means, I probably do not know what "flapdoodle" means, either.

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A definition should not employ in the genus or differentia any part or derivative of the word to be defined. It is of no value to be told that "an inheritance is that which is inherited," or that "gerrymandering is the process of applying the gerrymander.'

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In all sorts of exposition, but in definition especially, it

is necessary to remember the audience, to think of the person for whom you are defining, to consider what he probably knows and what he probably does not know, and to aim at simplifying matters and at making hard things easy.

The logical definition is most useful when it is accompanied by plenty of explanation and illustration. It is the final step in a process of thinking, involving many trials, partial definitions, selections and rejections, and tests of accuracy.

108. Assignments in Supplying or Narrowing the Genus.

In the following the genus is missing or else is too large to be of service. Supply it if it is missing; find a smaller genus, if it is too large; and perfect the definition.

1. A dog is an animal that eats flesh.

2. A coward is an individual who runs away.

3. A bicycle is a machine with two wheels.

4. A fly has two wings.

5. A novel is written in prose.

6. A pipe organ is played by the use of air currents.

7. A friend is an associate that can be trusted.

8. Clearness is an essential of discourse.

9. Physiography is all about the earth.

109. Assignments in Supplying or Completing the Differentia.

In the following the differentia is missing or else is not sufficiently specific, that is, fails to give a detail that is distinctive, characteristic, peculiar, and exclusive. Perfect each definition.

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"Manifest Destiny" was

"The Stalwarts were .
Quarantine is
"54-40 or fight" was

A mugwump was
A lyric is.

The Embargo was
Law is..

Au "Insurgent" is
C.O.D. is..

a man.

to read and think.

activity.
activity.

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of honor.

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110. Assignments in Abstracting Definitions.

Abstract a logical definition from the following passages; that is, pick out from each passage the genus and the differentia for the word italicized in each. You may have to infer the genus or part of the differentia.

1. "Prophecy" has, for about a century, narrowed itself, in common parlance, to the sense of "prediction"; and there are many readers of the Bible to whom the term suggests nothing more than the foretelling of the future. It is, of course, true that the Hebrew prophets dealt with the future, as they dealt with the present and the past. But the reference to future time is not the sole, nor even the chief, function of prophecy. The pro- in prophecy is not the pro- that

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