The fatal errors of life are not due to man's being unreasonable: an unreasonable moment may be one's finest moment. They are due to man's being logical.
There are so many errors and misstatements in that list that I won't even begin to name them. Obama was right about one thing, though - Islam has always been a part of America's story.
Eratosthenes's only tools were sticks, eyes, feet, and brains; plus a zest for experiment. With those tools he correctly deduced the circumference of the Earth, to high precision, with an error of only a few percent. That's pretty good figuring for 2200 years ago.
For truth is strong next to the Almighty. She needs no policies or stratagems or licensings to make her victorious. These are the shifts and the defences that error uses against her power.
A well informed public opinion is essential to the growth of political and social awareness. Only he who is informed can comment intelligently on his nation's development and only by such comments can errors be corrected and progress stimulated