Let every nation know, whether it wishes us well or ill, that we shall pay any price, bear any burden, meet any hardship, support any friend, oppose any foe to assure the survival and the success of liberty.
The assumption that nature is all there is, and that nature has been governed by the same rules at all times and places, makes it possible for natural science to be confident that it can explain such things as how life began.
If you have it and you know you have it, then you have it. If you have it and don't know you have it, you don't have it. If you don't have it but you think you have it, then you have it.