Here I answered:

“Since then your serene majesty and your lordships seek a simple answer, I will give it in this manner, neither horned nor toothed: Unless I am convinced by the testimony of the Scriptures or by clear reason (for I do not trust either in the pope or in councils alone, since it is well known that they have often erred and contradicted themselves), I am bound by the Scriptures I have quoted and my conscience is captive to the Word of God. I cannot and I will not retract anything, since it is neither safe nor right to go against conscience.

“I cannot do otherwise, here I stand, may God help me, Amen.”

Luther’s Works 32:112