Final answer:
Robespierre stated that terror was necessary to stifle the internal and external enemies of the Republic during his speech in the Reign of Terror, highlighting the need for extreme measures to preserve the republic.
Step-by-step explanation:
Maximilien Robespierre, a prominent figure during the French Revolution, gave a speech where he articulated that terror was a necessary instrument to achieve the goals of the revolution. He stated, "We must smother the internal and external enemies of the Republic or perish with them. Now, in this situation, the first maxim of your policy ought to be to lead the people by reason and the people's enemies by terror." This was during a time known as the Reign of Terror, a period characterized by extreme violence and the execution of numerous perceived enemies of the revolutionary government from 1793 through 1794. Robespierre and the Committee of Public Safety believed that such drastic measures, including the use of the guillotine, were necessary to preserve the republic and its ideals of liberty and equality.