The fact is, when wolves attack a herd, they always take the weakest animal.
At the autumn equinox, the gate is weakest.
Zwingli attacked the weakest part of Luther's theory - the ubiquity of the body of Christ; and Luther attacked Zwingli's exegesis of the words of the institution.
The weakest part of the ship was the upper part i.e the top strakes.
The girls voted out the " weakest link " by chanting " Send him off !
