Who said "Do not say 'if' - say 'since we shall certainly succeed.'"?

This quote is attributed to John Brown.

Do not say 'if' - say 'since we shall certainly succeed.' - John Brown

"Do not say 'if' - say 'since we shall certainly succeed.'"

John Brown Motivation

Abolitionist, Militant American 1800–1859

"I John Brown am now quite certain that the crimes of this guilty land will never be purged away but with blood."

"Let us do our duty."

"The Bible is the word of God and is to be obeyed."

"I am here to lay down my life for the cause of justice."

"I believe in working hard for what you want."

"Never underestimate the power of determination."

"I don't need a reason to fight."

"The most important thing is the mission. Nothing else matters."