In previous lessons, we learnt, logic is the study of the methods and principles used to distinguished correct from incorrect reasoning.

When talks about proposition, it means a declarative statement capable of being true or false. Example; This book is boring– declarative statement which requires an answer of either being true or false.

Three types of proposition.

1. Hypothetical proposition

These is the type of proposition between the subject and predicate which is asserted conditionally

Example if not rains, he will not come

ii.  If he comes I will accompany him.

2. Disjunctive proposition

In disjunctive proposition, the assertion is alternation

Example Either he is brave or he is strong.

ii. Either he is happy or cannot take revenge.

3. Categorical proposition

These is type of proposition between the subject and predicate without any condition. It has the structure of Quantifier + subject+ copular + predicate.

Example All boys are brilliant, Some beans are logs, No rod is stick.

Here are the structures

Quantifier=” All, No and Some “

Subject = “Boys, Beans and Rod “

Copular=  “are and is “

In every categorical statement or proposition, there exist universal or particular.

Universal proposition refers to all members of the class denoted by the subject term.

Particular statement or proposition refers to only some members of the class denoted by the subject term.

Quantity refer to the member of a given class in a proposition.

Quality also refer to a statement denies that one class is wholly or partially included another class.

Name  form           Quantity.     Quality 

A.     All S are P.   Universal  Affirmative

E.     No  S are P.   Universal.  Negative

I.     Some S are P particular Affirmative

O. Some S are not P particular Affirmative

Note the kinds of proposition

A proposition – universal Affirmative

E- proposition – universal negative

I- proposition – particular Affirmative

O- proposition – particular negative.

Share to friends, course mate. These are part of GST/GNS in first semester.

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