My top 10 highlights from the book:

1. Neither ever chose to be anything other than himself.

2. What the two had in common above all was unity of purpose and unyielding determination. They had set themselves on a mission.

3. A man who works for the immediate present and its immediate rewards is nothing but a fool.

4. Wilbur was little bothered by what others might be thinking or saying.

5. The brothers proceeded entirely on their own and in their own way. 

6. Every mind should be true to itself—should think, investigate, and conclude for itself. 

7. I wish to avail myself of all that is already known. 

8. Wilbur stressed that they would have to learn to accommodate themselves to circumstances. 

9. They were always thinking of the next thing to do; they didn't waste much time worrying about the past.

10.  In no way did any of this discourage or deter Wilbur and Orville Wright, any more than the fact that they had had no college education, no formal technical training, no experience working with anyone other than themselves, no friends in high places, no financial backers, no government subsidies, and little money of their own. Or the entirely real possibility that at some point, like Otto Lilienthal, they could be killed.