A test. Other races on other worlds have tried it and failed. Wiped themselves out. Overpopulated to the point of total ecological collapse. Destroyed themselves in wars. We've got to make sure that the human race discovers nanotechnology in the right way and develops it wisely, usefully. Not for power. Not for weapons. Humanely. Then we'll be ready to meet the other races that have succeeded, that have passed this test and become truly intelligent, truly adult.