Sentences
A sentence is the concrete, sensuous form of a proposition in just the way that a word is the concrete, sensuous form of a concept.
Just as the word “table” denotes the same Concept as “Tisch” does in German, so “The table is brown” is the same proposition as that expressed by “Der Tisch ist braun.” The linguistic symbols differ, the thought is the same. A given sentence may combine two or more propositions — i.e., make two or more identifications. “Plants need sunlight, and animals need food” is a single sentence, but two propositions. [1]
For example, the sentences "The sky is blue" and "Is the sky blue?" differ in their linguistic form, but they share the same propositional content: the identification of the sky's color. The proposition encompasses the essence of the judgment being made, independent of its expression.[1:1]
Propositions are not the only kind of locutions. Imperatives (“Sit up straight!”) issue orders; interrogatives (“Where is she?”) ask questions; conditional statements (“If it rains, we’ll get wet.”) make contingent judgments, etc. However, the base of all these is the basic form of propositions: the assertion that a predicate, P, applies in a specified way to a subject, S: “S is P.” ↩︎ ↩︎