The underlying message of The Wright Brothers is that although we understand flight so well today, and although we often take it for granted that we can fly to different cities, the truth is that it was visionary pioneers more than a century ago who first invented a flying machine and discovered the basic principles of flight. This fact is also easy to take for granted, but the true gravity of their intellectual success is nothing short of genius—both of them.
One lovely component of the historical story is that McCullough explains how the boys were different but complementary. Orville's outstanding mechanical abilities were instinctive and creative. He had a kind of intuitive understanding of machinery. His brother Wilbur was a genius in a more abstract way, often finding solutions to problems that other people never would have imagined. His power to understand the abstract principles of physics enabled their strategies to develop.
This is really a statement about the brother's moral success, too. Instead of falling prey to the trap of competition (which most brothers choose), the brothers loved each other and celebrated their differences. It was this fundamental respect between them that allowed them to be collaborators. The meaning is implicit and true: families who support each other foster intuitive people, and through collaboration, humans are capable of tremendous feats.
