"One Man's Meat Is Another Man's Poison"
Context: Lucretius, in Book IV, attempts to explain the senses: sight, sound, smell, taste. In speaking of taste, he explains that flavor is perceived when food is squeezed in the mouth and the juices distributed through the pores of the palate. Smooth juices give a pleasant taste, while rough ones are unpleasant. He further explains that food that might be good for one animal would not be good for another because of the different structure of the food and of the bodies. Similarly when the body structure is altered by sickness, something which is ordinarily sweet will taste bitter. Lucretius' idea about meat and poison was used by Beaumont and Fletcher, in 1647, in Love's Cure (Act III, sc. ii) as, What's one man's poison . . ./ Is another's meat or drink." Lucretius says it this way:
Next I will explain how different food is sweet and nourishing for different creatures, and why what is sour and bitter for some may yet seem very delicious to others, why there is so great a difference and distinction in these things that what is one man's meat is another man's rank poison. . . . Besides, hellebore is rank poison to us, but given to goats and quails makes them fat.