Another name for sentences like those just formed, is proposition, a proposition being the expression of one thought. But since a proposition is the statement of a judgment, it must contain two ideas. One of these, denoting that of which something is asserted, we call the subject; the other, denoting what is said of the subject, we call the predicate. The relation between these two ideas cannot always be expressed by means of two words. If we wish to assert a relation between water and freshness, we must use at least three words, Water is fresh; the word is contains little, if any, meaning, but is necessary for the grammatical expression of the thought.
Although a proposition must contain at least two ideas, it may contain any number of them. For example, I may expand the proposition, Children play, by additional ideas, telling (1) whose children, (2) a characteristic of the children, (3) what they play, (4) where they play, (5) when they play,—My neighbor’s little children play hide and seek in their yard every evening. Still I have only one proposition, for the number of propositions in a sentence depends on the number of judgments, or thoughts, expressed,—in other words, on the number of assertions made; and here there is but one, that made essentially by the verb play.
All sentences, however, are not single propositions, for in building sentences we often go a step further than seeing the relation between ideas, that is, we see the relation between thoughts; and so, instead of combining mere words, we combine whole propositions into one sentence. Take, for example, the two propositions, Children play, and Children enjoy play. I may see that the second fact is a cause of the first, and, by combining the two so as to bring out this relation of cause and effect, get the sentence, Children play because they enjoy it, wherein I substitute the pronouns they and it for the already known words children and play.
Or take the two propositions, The lion roared, and The hyena laughed. I may wish to tell some one that these two actions were related in time, occurring simultaneously; I do this by saying, The lion roared and the hyena laughed, where I have one sentence, but made of two propositions, because conveying two thoughts. I might put in other thoughts, telling (1) which lion, (2) why he roared, (3) how long the hyena laughed,—The lion that was kept in the cage near the door roared because the keeper did not bring his food, and the hyena laughed till he had set all the animals around him in an uproar. Here I have one sentence containing five thoughts, therefore made up of five propositions.
However, it is not with composition, the building up of sentences, that we are to concern ourselves, so much as with an examination into the structure of the finished product. Now, when we study the structure of the human body, we look upon it first as a symmetrical whole, then we separate it into its largest, most distinct members,—the head, the trunk, the arms, the legs. After we have noted the relations of these parts, we take up each part as a whole and proceed again in the same way. In analyzing sentences we shall pursue the same method.
Every sentence is a unit just as the body is; like the body, too, it is made up of smaller units. In studying its structure we should first of all find the units which compose the sentence-unit. If the sentence is a single proposition, the constituent units are, of course, the subject and the predicate. But if the sentence is a combination of propositions, as is oftener the case, then its chief units are these propositions. Therefore, as a foundation for the analysis of sentences, we must be able to determine readily how many propositions a given sentence contains. Our first exercise will be devoted to this end.
Exercise 1
Resolve the following sentences into single propositions. Remember that the number of propositions depends on the number of assertions made.
1. There are thousands of years between the stone hatchet and the machine shop.—C. W. Eliot.
2. All along the Atlantic, the country is bordered by a broad tract, called the tierra caliente, or hot region, which has the usual high temperature of equinoctial lands.—Prescott.