unreasoning

The specter of this virus fills some of our most stalwart souls with unreasoning dread even when it is no immediate threat.

Yet it's plain that he thinks a little worse of himself for allowing his judgment to overmaster his unreasoning dread.

I found myself trembling all over with an unreasoning fear, for there was something uncanny about the whole affair.

The sight of their stricken comrades, however, only seemed to drive the herd into deeper depths of dumb, unreasoning madness.