The Art of War by active 6th century B.C. Sunzi

41. He who exercises no forethought but makes light of his opponents is

sure to be captured by them. [Ch’en Hao, quoting from the _Tso Chuan_, says: "If bees and scorpions carry poison, how much more will a hostile state! Even a puny opponent, then, should not be treated with contempt."]