In their public statements and glossy planning documents, the men who run Saudi Arabia talk boldly about an exciting future of prosperity and innovation built on full integration into the global economy and the development of a “knowledge society” of educated citizens.

They seldom mention the other Saudi Arabia — a retrograde, anti-intellectual and often cruel society gripped by religious extremism that has surfaced again in the case of Hamza Kashgari. His story is an almost perfect microcosm of the dilemma facing King Abdullah and the princes as they try to balance their push for modernization with their need to maintain religious purity.

Kashgari is a 23-year-old writer and blogger who foolishly posted tweets on February 4 revealing doubts about his fealty to, and the perfection of, the Prophet Muhammad. It is a fundamental tenet of Islam that Muhammad was human, not divine, and therefore by definition had faults and weaknesses. But in Saudi Arabia, it is not permitted to say so, as Kashgari should have known — just as he should have realized that Twitter posts are not private.

When the Saudi religious authorities accused him of blasphemy and demanded his “trial” and execution, Kashgari deleted his tweets and fled to Malaysia — another mistake, because Malaysia, a Muslim country, promptly sent him back to Saudi Arabia. He is now in custody, awaiting a grim fate. Apostasy is a capital offense in Saudi Arabia.