Also in the video ‘how much do you know?’ At 11.00 when referring to question 6. Gerard makes the same mistake
a) BAC, ???, BID
“Of the four remaining candidates, the only one in which C is distributed is CAD, since rule six is vacuously satisfied, the proposition CAD satisfies all the rules and will give us a valid syllogism. ”
However this is not a valid syllogism because the B term is distributed being the subject term in the universal affirmative proposition yet the B term is undistributed as the subject term in the particular affirmative proposition that is the conclusion to the syllogism. Rule six is not satisfied (no term can be distributed in the conclusion that is not distributed in the premise) and since all six rules must be satisfied in order for a syllogism to be valid, this syllogism is invalid.