Another of his miscellaneous works, probably of a moral and didactic character, was known by the name of Protreptica. It is possible that all of these works[27], as well as the Scipio, formed part of the Saturae, or Miscellanies, under which title Ennius composed four, or, according to another authority, six books. The Romans looked upon Lucilius as the inventor of satire in the later sense of that word[28];--he having been the first to impress upon the satura the character of censorious criticism, which it has borne since his time. But there was another kind of satura, of which Ennius and Pacuvius in early times, and Varro at a somewhat later time, were regarded as the principal authors. This was really a miscellany treating of various subjects, in various metres, and, as employed by Varro, was written partly in prose, partly in verse. This kind of composition, as well as the Lucilian satire, arose out of the old indigenous satura or dramatic medley, familiar to the Romans before the introduction of Greek literature. When the scenic element in the original satura was superseded by the new comedy introduced from Greece, the old name was first applied to a miscellaneous kind of composition, in which ordinary topics were treated in a serious but apparently desultory way; and even as employed by Lucilius and Horace the satura retained much of its original character. The satires of Ennius were written in various metres, iambic, trochaic, and hexameter, and treated of various topics of personal and public interest. The few passages which ancient authorities quote as fragments from them are not of much value in themselves, but when taken in connexion with the testimonies as to their character, they are of some interest as showing that this kind of composition was a form intermediate between the old dramatic satura and the satire of Lucilius and Horace. It is recorded that in one of these pieces, Ennius introduced a dialogue between Life and Death;--thus transmitting in the use of dialogue (which appears very frequently in Horace and Persius) some vestige of the original scenic medley. Ennius also appears, like Lucilius and Horace, to have communicated in his satires his own personal feelings and experience, as in the fragment already quoted:-- Nunquam poetor, nisi si podager. Further satire, in the hands of its chief masters, aimed at practical moral teaching, not only by precept, ridicule, and invective, and by portraiture of individuals and of types, but also by the use of anecdotes and fables. This last mode of inculcating homely lessons on the conduct of life is common in Horace. It appears, however, to have been first used by Ennius. Aulus Gellius mentions that Aesop's fable of the field-lark and the husbandman 'is very skilfully and gracefully told by Ennius in his satires'; and he quotes the advice appended to the fable, 'Never to expect your friends to do for you what you can do for yourself':