CBSE Book Class 11 Philosophy Terms and Propositions

Terms and Propositions

Nature of propositions

A proposition is a unit of reasoning or logical thinking. Both premises and conclusion of reasoning are propositions. Since propositions are so important, we must know what a proposition is? A proposition is that which is believed to be true or false or doubtful. It is a unit of logical thinking in the sense that it is asserted and expressed in the form of proposition. For example "All men are mortal", "No child is a voter", "Some cats are black", "Ram is a student of this school" etc.

Types of proposition

From the view point of composition and construction propositions are either simple or compound. A simple proposition is a simple sentence having one verb whereas a compound proposition is a combination of two individual propositions. "New Delhi is the capital of India", "Two plus two make four", "Mrs. Indira Gandhi was mother of Rajiv Gandhi", "All voters are citizens" are simple propositions. Compound propositions have at least two simple propositions as components. "Mohan is a student and he is intelligent", "Either it rains, or we shall go for picnic", "If I get ticket, then I will go to see the match".

Classification of propositions

Propositions are classified in many ways. Let us take three classifications. The first classification is general classification of propositions which is based on the composition of propositions. The second classification is the traditional classification of propositions. The third classification is the one accepted by modern logicians.

Types of simple proposition

(i) Subject-Predicate Form:

There are three constituents in subject-predicate form of propositions, viz., subject term, predicate term and a copula. Subject of a proposition is that about which something is said. Predicate of a proposition states something about the subject. Between the subject term and the predicate term of every simple proposition occurs some form of the verb 'to be'. The verb 'to be' serves to connect the subject and the predicate term and is called 'copula'.

Copula is an essential part of every simple proposition. It is the joining link between the subject and the predicate. A proposition is the result of the combination of the subject term with the predicate term. If there is no copula, there is no connecting link between these two terms and consequently there is no proposition. Copula, however, is not a term. In the well-formed proposition copula is put in present tense.

(ii) Singular propositions:

Singular proposition has one definite person or thing or object as a subject. For instance, "Ram is a student of this school", "New Delhi is the capital of India", etc. A singular proposition is affirmative when predicate is assigned to subject. For instance, "Manmohan Singh is the Prime Minster of India". A singular proposition is negative when predicate is denied to subject. For instance, "Bombay is not the capital of India".

(iii) General (class membership) propositions:

The subject of a general proposition indicates a class of objects, persons or events. The terms like 'all' and 'some' designate quantity of subject term and thus are called quantifiers. Quantifiers indicate as to how the subject term is wholly or partially connected to the predicate. For instance, "Some cats are black" indicates that some members of a class 'cat' are 'black.' Whereas in the proposition "All cats are mammals" the quantifier refers to all the members of the subject class 'cat'. The former proposition is particular the latter is universal. Particular proposition is of two types, affirmative and negative. Similarly, universal proposition is of two types, affirmative and negative.

Relational propositions :

Relational propositions, though may be simple, yet there are different from subject - predicate form of propositions. Relational propositions highlight relation between two or among more objects, things, or persons. For instance, "Mrs Indira Gandhi was mother of Rajiv Gandhi". Here relation of mother and son is stated. "Ram told about Sohan to his teacher", highlights relationship among three persons. Relations that hold between two individuals are called 'binary' or 'dyadic' relations. Relations that hold among three individuals or things are called 'triadic relations'. Tetradic relations are expressed by the four elements or things. For instance, "Ram sold his cow to Sohan for a handful of rupees".

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