New Delhi, Aug. 30 -- Elon Musk once warned that artificial intelligence (AI) could become humanity's greatest existential threat. Now he imagines the same technology making money almost meaningless. Yuval Noah Harari sees a different danger: before AI makes us richer, it may make us less free.

Their recent conversations with The Economist offer two contrasting visions. Musk looks at what AI can produce. Harari asks what it might do to human agency. Both agree AI will transform civilization. The question is what humans may lose.

In a conversation with The Economist's editor-in-chief Zanny Minton Beddoes, Musk predicted that AI could surpass the combined intelligence of humanity within about five years.

Within a decade, he suggested, hu...