§ 738. Of the two premisses, one conjunctive and one simple, the conjunctive is considered to be the major, and the simple premiss the minor. For the conjunctive premiss lays down a certain relation to hold between two propositions as a matter of theory, which is applied in the minor to a matter of fact. § 739. Taking a conjunctive proposition as a major premiss, there are four simple minors possible. For we may either assert or deny the antecedent or the consequent of the conjunctive. Constructive Mood. Destructive Mood. (1) If A is B, C is D. (2) If A is B, C is D. A is B. C is not D. .'. C is D. .'. A is not B. (3) If A is B, C is D. (4) If A is B, C is D. A is not B. C is D. No conclusion. No conclusion. § 740. When we take as a minor 'A is not B ' (3), it is clear that we can get no conclusion. For to say that C is D whenever A is B gives us no right to deny that C can be D in the absence of that condition. What we have predicated has been merely inclusion of the case AB in the case CD. [Illustration] § 741. Again, when we take as a minor, 'C is D' (4), we can get no universal conclusion. For though A being B is declared to involve as a consequence C being D, yet it is possible for C to be D under other circumstances, or from other causes. Granting the truth of the proposition 'If the sky falls, we shall catch larks,' it by no means follows that there are no other conditions under which this result can be attained. § 742. From a consideration of the above four cases we elicit the following _Canon of the Conjunctive Syllogism._ To affirm the antecedent is to affirm the consequent, and to deny the consequent is to deny the antecedent: but from denying the antecedent or affirming the consequent no conclusion follows. § 743. There is a case, however, in which we can legitimately deny the antecedent and affirm the consequent of a conjunctive proposition, namely, when the relation predicated between the antecedent and the consequent is not that of inclusion but of coincidence--where in fact the conjunctive proposition conforms to the type u. For example-- _Denial of the Antecedent_. If you repent, then only are you forgiven. You do not repent. .'. You are not forgiven. _Affirmation of the Consequent_. If you repent, then only are you forgiven. You are forgiven. .'. You repent. CHAPTER XXI. _Of the Reduction of the Partly Conjunctive Syllogism._