"It is madness for sheep to talk peace with a wolf"

This quote by Thomas Fuller is a caution versus naivety and trusting those who can not be relied on. It is a metaphor for the idea that it is absurd to try to work out with somebody who has malicious objectives. The wolf in this metaphor represents somebody who is untrustworthy and has destructive intentions, while the sheep represents someone who is ignorant and trusting. The quote is warning us that it is silly to attempt to negotiate with somebody who has harmful intents, as they will not be truthful or trustworthy. It is a suggestion to be cautious of those who can not be trusted and to be familiar with the possible effects of trusting somebody who has destructive intents.