 discuss the unit 1, semester 2, standard form of categorical syllogism. In this unit, dear learners, we will discuss the basic points. They are standard form of categorical syllogism, structure of categorical syllogism, what is smooth, what is figure, band diagram technique for testing syllogism, and finally there is a section like harder readings. In harder readings, you have to get some books which you have to consult for knowing more to the unit that is standard form of categorical syllogism. Now, dear learners, this unit introduces you standard form of categorical syllogism. It includes the definition as well as the structure of the categorical syllogism. Apart from this, you get the concepts like mood, figure of syllogism, and the band diagram technique for testing syllogism. Dear learners, a standard form categorical syllogism is a didacty argument which contains two categorical propositions. And from two categorical propositions, they can jointly conclusion is drawn. As for instance, dear learners, you may take an example. All philosophers are rationalists. All mathematicians are philosophers. Therefore, all mathematicians are rationalists. Dear learners, this is an example of standard form categorical syllogism. Now, you see, dear learners, what is standard form of categorical syllogism? A syllogism is a kind of didacty argument in which a conclusion is drawn from two premises taken together. A categorical syllogism is a didacty argument consisting only of categorical propositions. Now, dear learners, there is another section which you have to know that is structure of categorical syllogism. A categorical syllogism contains three terms, each of which occurred in the two premises from which the conclusion follows. A standard form categorical syllogism consists of standard form categorical propositions. Its premises and conclusion are all standard form categorical propositions. The three terms of the standard form categorical propositions occur twice in the syllogism. The three terms are called the major term, the minor term, and the middle terms respectively. The term that occurs as the predicate of the conclusion is called the major term of the conclusion, is called the major term of the syllogism. And the term that occurs as the subject term of the conclusion is called the minor term of the syllogism. The term that occurs in both the premises but not in the conclusion is called the middle term. Dear learners, now you have to take an example of the standard form of categorical syllogism. You see, all Greeks are humans. All Athenians are Greeks. Therefore, all Athenians are humans. The term human is the predicate of the conclusion. And thus, it is the major term of the syllogism. Athenians is the subject of the conclusion. And as such, it is called the minor term. The term Greek occurs in both the premises. And as such, it is the middle term of the syllogism. The premise, all Greeks are humans is the major premise because the major term human occur in this premise. The premise, all Athenians are Greeks, is the minor premise. Since the minor term, Athenians occur in this premise. In the standard form categorical syllogism, the major premise is stated first, the minor premise, the second, and the conclusion last. Major premise and the minor premise are not defined in terms of their position, but in terms of their position of major term and minor term respectively. Now, dear learners, you have to know a basic concept that is mood, then you see what is mood there. The mood of a standard form categorical proposition is determined by the forms of the standard form categorical proposition it contains. Since the above syllogism contains all a proposition that is both the premises and the conclusion are a propositions, therefore the mood of the syllogism is a, a, a. However, the mood of a standard form categorical syllogism does not wholly or completely determine its form. Two syllogisms may have the same mood, but may differ in form. Let us take two syllogisms and see that they have the same mood, but differ in form. Dear learners, you see all philosophers are intellectuals, some scientists are intellectuals, therefore some scientists are philosophers. Second, you see all scientists are philosophers, some scientists are mathematicians, therefore some mathematicians are philosophers. In both the syllogisms, major premises are universal affirmative, that is we indicate as capital A propositions. Minor premises are particular affirmative, that is high propositions, and the conclusions are particular affirmative propositions that we write as capital I, high propositions. Therefore the syllogisms are moved off, are moved, are off, moved, all, but their form is different. In order to show how the syllogisms, two syllogisms differ in forms, we have to replace the terms of the propositions that is the major term, minor terms, and the middle terms by the letters P, S, and M respectively. The forms of the two syllogisms are as follows. All P is M, some S is M, therefore some S is P. The second example you take, all M is P, some M is S, therefore some S is P. Their differences lies in the fact that the position of the middle term is different in the two syllogisms. In the first, the middle term is the predicate in both the premises, whereas in the second, the middle term is the subject in both the premises, thus it is seen that these two syllogisms in spite of having the same mood are different in form. The mood of syllogism cannot completely tie in the form of a syllogism. The form of a syllogism may be completely described by stating its mood and figure. Now, dear learners, you have to know another very basic concept. In case of standard form of categorical syllogism, that is figure, now dear learners, you see figure indicates the position of the middle term in the syllogism. Now, as you know that middle term is that term which occur in both the premises. Depending on the position of the middle term in the premises, we have four different figures those syllogisms may have. The middle term may be the subject of the major premise and predicate term of the minor premise or it may be the predicate term of both the premises. Or it may be the subject term of both the premises. Or it may be the predicate term of major premise and subject term of the minor premise. These different possible positions of the middle term constitute the first, second, third and fourth figure respectively. Dear learners, the four figures are schematized in the following area. Now you can see the blackboard. The four figures, you see the blackboard. Now dear learners, you see the first figure that is M is the first figure. Now you see the second figure. Now you see the second figure that is, this is second figure. And the third figure you see, third figure you see M P M S M S then S P. So first figure, second figure, third figure. Then the last one that is fourth figure. Last one you see that is fourth figure. P M M S therefore S P. So this is all about the four figures. First figure, second figure, third figure and fourth figure. Dear learners, does the mood and the figure together constitute the form of the standard form categorical syllogisms? There are four kinds of propositions. A, E, I, N, O. A syllogism has got two premises. Hence we may have 16 possible moods in each figure. Again, there are four figures. So we have 16 into 4, 64 possible moods in all the four figures. Again, each of the 16 four combinations may have four forms. Thus in this sense, there are 64 into 4, 1256 moods in all the four figures. Out of these 256 moods, some are valid and some are invalid. Now, dear learners, after going through these concepts, you have to test yourselves. So there are some questions given to you. You have to answer. So first one, what is standard form categorical syllogism? Second one, what are the three terms occur in standard form categorical syllogism? Question three, what is mood? And how many figures are in syllogism? Question four. Question five, fill out the blanks. So there are some questions given to you. A categorical syllogism contains dash terms. Figure indicates the position of the dash term, dash, and dash constitutes the standard form categorical syllogism.