The Stag, the Wolf, and the Sheep
A stag asked a sheep to lend him a measure of wheat and said that the wolf would be his surety. The sheep, fearing some fraud was intended, excused herself, saying; "The wolf is accustomed to seize what he wants and to run off and you, too, can quickly outstrip me in your rapid flight. How then shall I be able to find either of you when the day of payment comes?"
Two blacks do not make one white.