Leonard Nimoy, the actor who portrayed Spock in the “Star Trek” television series, passed away at 83 on Friday. The popular Boston-born poet, singer, photographer and film director died from chronic obstructive pulmonary disease, which he believed was the result of his cigarette smoking habit. Nimoy had quit three decades ago.

Nimoy’s depiction of Spock was his most iconic role. The actor portrayed the half-human, half-Vulcan character flawlessly, effectively bringing logic and depth to the part. Nimoy’s Spock was wise, intelligent and insightful, and he often said brilliant things. Check out our list of some of Spock’s best quotes:

“I’ve never understood the female capacity to avoid a direct answer to any question.” – “This Side of Paradise,” 1967

“If there are self-made purgatories, then we all have to live in them. Mine can be no worse than someone else's.” – “This Side of Paradise,” 1967

“After a time, you may find that having is not so pleasing a thing after all as wanting. It is not logical, but it is often true.” – “Amok Time,” 1967

“Speed is essential.” – “Who Mourns for Adonais?” 1967

“May I say that I have not thoroughly enjoyed serving with humans? I find their illogic and foolish emotions a constant irritant.” – “Day of the Dove,” 1968

"You Earth people glorify organized violence for 40 centuries, but you imprison those who employ it privately.” – “Dagger of the Mind,” 1966

“Evil does seek to maintain power by suppressing the truth.” – “And the Children Shall Lead,” 1968

“No one can guarantee the actions of another.” – “Day of the Dove,” 1968

“I have noted that the healthy release of emotion is frequently very unhealthy for those closest to you.” – “Plato’s Stepchildren,” 1968

“We must acknowledge once and for all that the purpose of diplomacy is to prolong a crisis.” – “The Mark of Gideon,” 1969