Your search for "Doubt, of whatever kind, can be ended by action alone. - Thomas Carlyle 1795 - 1881" revealed the following:

RW-11.3- Resolve and thou art free. - Henry Wadsworth Longfellow 1807 - 1882

S2TDQ- Prejudices are the chains forged by ignorance to keep men apart. -&- Insults are the arguments employed by those who are in the wrong.