What is the opposite of critical thinking, in this account?

Dogmatic and ideological thinking — holding beliefs as fixed and beyond questioning.

Critical thinking is defined partly by its contrast. Its opposite is not "positive" or "trusting" thinking; it is dogmatism (treating a doctrine as settled truth no evidence could revise) and ideology (a closed system of belief that explains everything in advance). Both share one feature: they place certain claims outside the reach of examination. Critical thinking, by contrast, keeps claims open to being tested, and — crucially — a critical thinker can change their mind when the reasons demand it. That willingness to revise is intellectual openness, and it is exactly what dogma forbids.