Normally, however, Galen upholds both reason and experience as criteria of truth against the opposing schools of Dogmatics and Empirics. The former attacked experience as uncertain and impossible to regulate, slow and unmethodical. The latter replied that experience was consistent, adaptable to art, and proof enough.[688] Galen’s chief objection to the Empirics is that they reject reason as a criterion of truth and wish the medical art to be irrational.[689] “The Empirics say that all things are discovered by experience, but we say that some are found by experience and some by reason.”[690] Galen also objects to Herodotus’s explanation of the medical art as originating in the conversation of patients exposed at crossroads who told one another of their complaints and recoveries and thus evolved a fund of common experience.[691] Galen criticizes such experience as irrational and not yet put into scientific form (οὔπω λογική). Of the Empirics he tells us further that they regard phenomena only and ignore causes and put no trust in reasoning. They hold that there is no system or necessary order in medical discovery or doctrine, and that some remedies have been discovered by dreams, others by chance. They also accepted written accounts of past experiences and thus to a certain extent trusted in tradition. Galen argues that they should test these statements of past authorities by reason.[692] His further contention that, if they test them by experience, they might as well reject all writings and trust only to present experience from the start, is a sophistical quibble unworthy of him. He adds, however, that the Empirics themselves say that past tradition or “history” (ἱστορία) should not be judged by experience, but it is unlikely that he represents their view correctly in this particular. In another passage[693] he says that they distinguish three kinds of experience, chance or accidental, offhand or impromptu, and imitative or the repetition of the same thing. In a third passage[694] he repeats that they held that observation of one or two instances was not enough, but that oft-repeated observation was needed with all conditions the same each time. In yet another place[695] he says that the Empirics observe coincidences in things joined by experience. He himself defines experience as the comprehending and remembering of something seen often and in the same condition,[696] and makes the good point that one cannot observe satisfactorily without use of reason.[697] He also admits in one place that some Empirics are ready to employ reason as well as experience.[698] [Sidenote: How the Empirics might have criticized Galen.]