(Written by Cougar Trollhammer Draven, who was banned.)

Affirming a Disjunct/ Affirming One Disjunct or Asserting an Alternative or Improper Disjunctive Syllogism or Alternative Syllogism, Fallacy of the

Description: The alternative syllogism is of the form "p or q, p, therefore not q". In practice, this may be correct, as in the case "Today is either Saturday or Sunday". Clearly, the day cannot be both Saturday and Sunday, so an "exclusive OR" (XOR) is the case. If that is so, then an alternative syllogism is sound.

Example: If, however, an inclusive or (boolean OR) is involved, such as "My class ring is black or silver", then the conclusion "My class ring is silver, therefore it is not black" is invalid. My class ring is silver and black, which is covered.

Syllogistic Fallacy

Description: A formal fallacy of several types. Put simply, a syllogistic fallacy is a form of categorical syllogism that does not validate.

Example: A few types of this are the Affirmative Conclusion from Negative Premiss (and conversely, the Negative Conclusion from Affirmative Premiss), the Four-Term Fallacy, and the Undistributed Middle.