What does Mock on mock on Voltaire Roussseau mean?

"Mock on, mock on, Voltaire, Rousseau" is a line from William Blake's poem "The Tyger." It suggests that even great thinkers like Voltaire and Rousseau may not fully comprehend the complexity and awe-inspiring nature of the world symbolized by the tiger in the poem. The repeated "mock on" emphasizes the idea that humans can only grasp a limited understanding of the divine and mysterious aspects of creation.