Salman Rushdie emphasizes that when any system of ideas, whether rooted in religion or secular beliefs, is deemed sacred, it limits the freedom to critique or challenge those ideas. This immunity from scrutiny can stifle open dialogue, as individuals may feel unable to express dissenting opinions without fear of backlash. Such a situation constrains the marketplace of ideas, preventing healthy debate and intellectual growth.

The essence of Rushdie's argument is that true freedom of thought thrives on the ability to question and challenge beliefs. By placing any ideology beyond criticism, society risks becoming stagnant and intolerant. To preserve the freedom to think independently, it is essential to maintain the right to critique all ideas, allowing for a diverse range of voices and perspectives to coexist.