The word "duty" is often employed to translate the Greek term which we are rendering by "propriety." Any translation is no more than a choice of evils, since we have no real equivalent for the term. It was applicable not merely to human conduct, but also to the acting of the lower animals, and even to the growth of plants. Now, apart from a craze of generalization we should hardly think of the "stern daughter of the voice of God" in connection with an amoeba corresponding successfully to stimulus, yet the creature in its inchoate way is exhibiting a dim analogy to duty. The term in question was first used by Zeno, and was explained by him, in accordance with its etymology, to mean what it came to one to do, so that as far as this goes, 'becomingness' would be the most appropriate translation. The sphere of propriety was confined to things indifferent, so that there were proprieties which were common to the sage and the fool. It had to do with taking the things which were in accordance with nature and rejecting those that were not. Even the propriety of living or dying was determined, not by reference to virtue or vice, but to the preponderance or deficiency of things in accordance with nature. It might thus be a propriety for the sage in spite of his happiness, to depart from life of his own accord, and for the fool notwithstanding his misery, to remain in it. Life, being in itself indifferent, the whole question was one of opportunism. Wisdom might prompt the leaving herself should occasion seem to call for it. We pass on now another instance of accommodation. According to the high Stoic doctrine, there was no mean between virtue and vice. All men indeed received from nature the starting-points for virtue, but until perfection had been attained they rested under the condemnation of vice. It was, to employ an illustration of the poet-philosopher Cleanthes, as though Nature had begun an iambic line and left men to finish it. Until that was done they were to wear the fool's cap. The Peripatetics, on the other hand, recognized an intermediate state between virtue and vice, to which they gave the name of progress and proficience. Yet so entirely had the Stoics, for practical purposes, to accept this lower level, that the word "proficience" has come to be spoken of as though it were of Stoic origin.