"In this work I have received the opposition of a number of men who only advocate the unobtainable because the immediately possible is beyond their moral courage, administrative ability, and their political prescience"

This quote by John Burns speaks with the problem of achieving progression despite resistance. He is recommending that some people hesitate to pursue the right away possible because it calls for ethical nerve, management capability, and political prescience. Simply put, they hesitate to take threats and place in the hard work required to make progress. Burns is suggesting that these people are content to advocate for the impossible since it is much easier than taking on the obstacle of the instantly possible. He is likely criticizing those who are unwilling to take threats as well as put in the initiative to make development. He is suggesting that progression is only possible when individuals are willing to take dangers and place in the effort necessary to make it occur.