"Why can't somebody give us a list of things  that everybody thinks and nobody says, and another list of things that everybody says and nobody thinks." ~Oliver Wendell Holmes


"Pure logical thinking cannot yield us any knowledge of the empirical world: all knowledge of reality starts from experience and ends in it....Because Galileo saw this, and particularly because he drummed it into the scientific world he is the father of modern physics-indeed, of modern science altogether." ~Einstein


"Regulated thought is a seeking. Sometimes a man seeks what he has lost.....Sometimes a man knows a place determinate, within the compass whereof he is to seek; and then his thoughts run over all the parts thereof, in the same manner as one would sweep a room to find a jewel; or as a spaniel ranges the field, till he find a scent; or as a man should run over the alphabet, to start a rhyme." ~Thomas Hobbes   1651


"The difficulty lies, not in the new ideas, but in escaping the old ones, which ramify, for those brought up as most of us have been, into every corner of our minds." ~John Maynard Keyes


"The Art of Thinking is the art of being one's self and this art can only be learned if one is by one's self." ~Ernest Dimnet

"As a single footstep will not make a path on the earth, so a single thought will not make a single pathway in the mind. To make a deep physical path, we walk again and again. To make a deep mental path, we must think over and over the kind of thoughts we wish to dominate our lives." ~Henry David Thoreau

     
“Many men owe the grandeur of their lives to the tremendous difficulties” ~Charles H. Spurgeon