What's one man's poison, signor,
Is another's meat or drink.

What is food to one, is to others bitter poison.

What is one man's safety is another man's destruction.

One man's justice is another's injustice; one man's beauty another's ugliness; one man's wisdom another's folly.

Men and the world are mutually toxic to each other.

That is what we want to destroy — this annihilation — this eating of man by an other man.

Fear is a poison that binds the minds of men and women to the same stone where Prometheus' liver is devoured forever by the cruel beaks of hungry birds.

After Bjartur had become a person of great worth, even he was prone to admit on occasion that life had sometimes been pretty hard in Summerhouses in the old days, but one has to take a few knocks if one wants to get on, surely, and anyway we never ate other folk's bread. Other folk's bread is the most virulent form of poison that a free and independent man can take; other folk's bread is the only thing that can rob him of independence and the one true freedom.

One man’s wickedness becomes all men’s curse.

yet of their own poison do they perish

And though this may seem to subtile a deduction of the Lawes of Nature, to be taken notice of by all men;whereof the most part are too busie in getting food, and the rest too negligent to understand; yet to leave all men unexcusable, they have been contracted into one easie sum, intelligble, even to the meanest capacity; and that is, Do not that to another, which thou wouldest not have done to thyselfe; which sheweth him, that he has no more to do in learning the Lawes of Nature, but, when weighing the actions of other men with his own, they seem too heavy, to put them into the other part of the balance, and his own into their place, that his own passions, and selfe love, may adde nothing to the weight; and then there is none of these Laws of Nature that will not appear unto him very reasonable.

What is one man's gain is another's loss.

[O]ne man's vulgarity is another's lyric.

One man's disobedience is another's derring-do.