"In fighting nature, man can win every battle except the last. If he should win that too, he will perish, like an embryo cutting its own umbilical cord"

This quote by Thor Heyerdahl talks to the power of nature and the limits of human control. Heyerdahl is recommending that while human beings can win fights versus nature, they can not eventually win the war. If they were to win the last fight, they would be cutting their own lifeline, like an embryo cutting its own umbilical cable. This implies that people depend on nature which any effort to manage it too much will result in their own destruction. Heyerdahl is alerting us that we must respect nature and its power, and that we ought to not try to control it too much. We must find a balance in between our needs and the needs of the environment, and aim to live in harmony with nature.