After 16 years of taking satirical aim at the hypocrisy of politics and the fatuousness of the news media, Jon Stewart said goodbye to “The Daily Show” on Thursday evening with a farewell broadcast that mixed wry parting shots with earnest displays of emotion and with a passionate speech urging his audience not to accept falsehoods and misinformation in their lives.

Mr. Stewart, 52, who has presided over this Comedy Central news-parody show since 1999, concluded his final episode with a spirited sermon against what he euphemistically described as “social-contract fertilizer.” (He also used a familiar and much stronger epithet.)

Blatant mendacity, Mr. Stewart said, has become ubiquitous and pernicious. “Whenever something’s been titled Freedom Family Fairness Health America, take a good long sniff,” he said.

The only way to combat the relentless intrusions of dishonest people, Mr. Stewart said, was through vigilance. “Their work is easily detected, and looking for it is kind of a pleasant way to pass the time,” he said.