Using, then, only affirmative hypothetical propositions in the major premise, there are four Moods: 

1.  The Simple Constructive—­

    If A is B, C is D; and if E is F, C is D: 
      But either A is B, or E is F: 
    .’.  C is D.

    If the Tories win the election, the Government will avoid
    innovation; and if the Whigs win, the House of Lords will
    prevent them innovating: 

     But either the Tories or the Whigs will win: 

     .’.  There will be no innovation.

2.  The Complex Constructive—­

    If A is B, C is D; and if E is F, G is H: 
      But either A is B, or E is F: 
    .’.  Either C is D or G is H.

    If appearance is all that exists, reality is a delusion; and
    if there is a substance beyond consciousness, knowledge of
    reality is impossible: 

     But either appearance is all, or there is a substance beyond
    consciousness: 

     .’.  Either reality is a delusion, or a knowledge of it is
    impossible.

3.  Simple Destructive—­

    If A is B, C is D; and if A is B, E is F: 
      But either C is not D, or E is not F: 
    .’.  A is not B.

    If table-rappers are to be trusted, the departed are spirits;
    and they also exert mechanical energy: 

     But either the departed are not spirits, or they do not
    exert mechanical energy: 

     .’.  Table-rappers are not to be trusted.

4.  Complex Destructive—­

    If A is B, C is D; and if E is F, G is H: 
      But either C is not D, or G is not H: 
    .’.  Either A is not B, or E is not F.

    If poetic justice is observed, virtue is rewarded; and if the
    mirror is held up to Nature, the villain triumphs: 

     But either virtue is not rewarded, or the villain does not
    triumph: 

     .’.  Either poetic justice is not observed, or the mirror is
    not held up to Nature.

Such are the four Moods of the Dilemma that emerge if we only use affirmative hypotheticals for the major premise; but, certainly, it is often quite as natural to employ two negative hypotheticals (indeed, one might be affirmative and the other negative; but waive that); and then four more moods emerge, all having negative conclusions.  It is needless to intimidate the reader by drawing up these four moods in battle array:  they always admit of reduction to the foregoing moods by obverting the hypotheticals.  Still, by the same process we may greatly decrease the number of moods of the Categorical Syllogism; and just as some Syllogisms are most simply expressed in Celarent or Cesare, so some Dilemmas are most simply stated with negative major premises—­e.g., The example of a Simple Constructive Dilemma above given would run more naturally thus:  If the Tories win, the Government will not innovate; and if the