We read in history of a female criminal in Athens, who succeeded in drinking the quantity of poison allotted as a fatal draught for the condemned with little or no injury to her health, by taking it at intervals. So being condemned, she took the poison in the prescribed quantity like the rest, but rendered it powerless by accustoming herself to it, and did not die like the rest. And as this excited great wonder, she was banished. But because disagreement is an evil, what she did was to make the poisonous matter agree with her own body by a process of habituation. Because what is truly and properly an evil is hurtful both always and to all.
Oil is beneficial to our bodies, but very much the opposite to many six-footed animals.
And is not hellebore sometimes food, sometimes medicine, and sometimes poison. And yet the benefits to the body from salt are innumerable and most important. Sea-water is injurious when drunk by land animals, but it is most suitable and useful to many who bathe their bodies in it and to fish it is useful and wholesome in both ways. Bread nourishes man, but kills hawks. We need not go farther than the four elements themselves, which, as every one knows, are beneficial when there is agreement, and bitterly opposed to nature when there is disagreement in the objects acted upon.