simply making a particular affirmative preposition. You are making a positive statement about some members of the class of Christians, that is, that some Christians are Catholics, not that all Christians are Catholics. 3.4 The Particular Negative Proposition (Some S is not P) It is the opposite of a particular Affirmative proposition. Although it belongs to the pair of Negative affirmative proposition it still remains different from the universal negative. The particular negative proposition denies something about some members of a class. For instance, if you say that some taxi drivers are not drunk. You are making a particular negative proposition; you are simply denying the attribute of being drunk to some, but not all taxi-drivers. MODULE 4 GENERAL INTRODUCTION UNIT 1: SYLLOGISMS 1.0 INTRODUCTION This study unit introduces you the different kinds of syllogisms. It will focus particularly on the categorical syllogism. The unit will also teach you rules for evaluating syllogisms. To a logician, a syllogism is an argument that contains at least three propositions, two of which are called the premises, and one the conclusion. But you should also keep in mind that there are some syllogisms that contain less or more than three propositions as we shall see latter. However, my main focus in this study unit is on the categorical syllogisms. Traditional syllogistic logic or Aristotelian logic deals only with categorical propositions. And, as stated earlier (unit 4). Categorical propositions are indicative or declarative sentences. They assert or deny relationship between classes. So, always remember that categorical syllogisms are arguments composed entirely of categorical statements. And, every categorical syllogism contains exactly three terms. For instance: · All men are mortal · Socrates is a man · Therefore Socrates is mortal. 3.1 Standard form, mood and figure Always keep in mind that the mastery of the above terms is very important for evaluating categorical syllogisms. Standard form Categorical syllogism has a standard form. It is the same everywhere and at any time. It contains some terms proper to it such as Middle term, major term and the minor term. You should
remember that the Middle term of a categorical syllogism is the term that occurs once in each premise. The major term of a categorical syllogism is the predicate term of the conclusion. The minor term of a categorical syllogism is the subject term of the conclusion. We can say that a categorical syllogism is in standard form only and only if the following conditions are met: a) The premises and the conclusion must be categorical statements in standard form such as (“All S are P”, “No S are P” “Some S are P” or “Some S are not P”.) b) The first premise contains the major term. c) The second premise contains the minor term. d) The conclusion is stated last.