James Boswell, The Life of Samuel Johnson:
“Theocritus is not deserving of very high respect as a writer; as to the pastoral part, Virgil is very evidently superiour. He wrote when there had been a larger influx of knowledge into the world than when Theocritus lived. Theocritus does not abound in description, though living in a beautiful country: the manners painted are coarse and gross. Virgil has much more description, more sentiment, more of Nature, and more of art. Some of the most excellent parts of Theocritus are, where Castor and Pollux, going with the other Argonauts, land on the Bebrycian coast, and there fall into a dispute with Amycus, the King of that country; which is as well conducted as Euripides could have done it; and the battle is well related. Afterwards they carry off a woman, whose two brothers come to recover her, and expostulate with Castor and Pollux on their injustice; but they pay no regard to the brothers, and a battle ensues, where Castor and his brother are triumphant. Theocritus seems not to have seen that the brothers have the advantage in their argument over his Argonaut heroes. The Sicilian Gossips is a piece of merit.”
“Callimachus is a writer of little excellence. The chief thing to be learned from him is his account of Rites and Mythology; which, though desirable to be known for the sake of understanding other parts of ancient authours, is the least pleasing or valuable part of their writings.”