"Anyone who has begun to think, places some portion of the world in jeopardy"

This quote by John Dewey suggests that when an individual starts to believe seriously about the world or their environments, they might question or challenge particular standards or beliefs. In doing so, they may destabilize or potentially threaten specific elements of the world they live in. This can be seen as an outcome of the person's important thinking and ability to challenge existing paradigms, which might bring about change and progress but also carry dangers and unpredictability.