A10649 Day11 Denying the antecedent

if A: if our tenured faculty members are all very politically conservative

then B:  then teachers who are tenured are all conservative

if not A: if none of our better teachers are tenured

then not B: then none of our better teachers are conservative

Attack: However, being a tenured teacher is not the only way to become politically conservative; that is to say, there may be a number of ways to become conservative in this context. In that way, though being one of tenured faculty members can be a sufficient condition for being conservative,  it is not a necessary one. Therefore, claiming that no better teachers are tenured cannot lead to the conclusion that none of the better teachers are conservative.