Keller argues that optimism is not just a mindset or a way of thinking, but a moral duty. She believes that it is our responsibility as humans to cultivate a positive outlook on life and to strive for a better world. Keller sees optimism as an essential component of progress, both for individuals and society as a whole.The essay also reflects on Keller's own life experience, as someone who overcame profound disabilities to become a successful writer, speaker, and activist. She writes about the challenges she faced and the ways in which she learned to cultivate optimism and a sense of hope in the face of adversity.