Part of this is often misquoted as "We have nothing to fear but fear itself," most notably by Martin Luther King, Jr. in his I've Been To The Mountaintop http://www.americanrhetoric.com/speeches/mlkivebeentothemountaintop.htm speech. Similar expressions were used in ancient times, for example by Seneca the Younger (Ep. Mor. 3.24.12 http://www.thelatinlibrary.com/sen/seneca.ep3.shtml): scies nihil esse in istis terribile nisi ipsum timorem ("You will understand that there is nothing dreadful in this except fear itself"), and by Michel de Montaigne: "The thing I fear most is fear", in Essays (1580), Book I, Ch. 17.
1930s, First Inaugural Address (1933)
Context: This is preeminently the time to speak the truth, the whole truth, frankly and boldly. Nor need we shrink from honestly facing conditions in our country today. This great Nation will endure as it has endured, will revive and will prosper. So, first of all, let me assert my firm belief that the only thing we have to fear is fear itself — nameless, unreasoning, unjustified terror which paralyzes needed efforts to convert retreat into advance. In every dark hour of our national life a leadership of frankness and vigor has met with that understanding and support of the people themselves which is essential to victory.
