There were various episodes where Vulcans did lie. For example, Spock did lie in episode The Menagerie and Vulcans from Enterprise series were often deceitful, like in The Andorian Incident.

Now, Spock is half human, so really isn't the best example. But, Vulcans from Enterprise era are entirely Vulcan and they did lie.

Is the question of truthfulness just like with their emotions - not a physiological condition, but rather a result of their cultural conditioning? Such conditioning which was not widespread in Enterprise era, but already is in TOS era. Are they really incapable of telling a lie or is it that they usually don't lie?

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    Perhaps they just tell the truth, from a certain point of view.
    – Jeff
    Commented Aug 11, 2011 at 18:07
  • 9
    Based on my recent viewing of Enterprise, the Vulcans are nothing but a race of liars. Commented Sep 2, 2011 at 15:18
  • 2
    It is also and quite frequently possible to "lie" while still also being 100% truthful in what you say. What you are saying may not be untruthful, but it also may not be the whole truth or may be deliberately misdirective.
    – eidylon
    Commented Sep 2, 2011 at 20:53
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    Frankly, Vulcans lie almost non-stop. Spock was simply telling a lie when he said that "Vulcans cannot lie". As @JackBNimble alluded to, T'pol on Enterprise lies -- for example when she claimed that a Vulcan ambassador had been badly injured in an attack by the Suliban. Not to mention, the lies and deceit of Valeris in Star Trek VI. In TOS Spock was always lying -- like in the Tholian Web and often to cover up the fact that he clearly emotional on an ongoing basis (he was often defensive, fascinated, loyal, proud... all emotions). Vulcans are nothing but a pack of liars.
    – Hack-R
    Commented Jan 30, 2016 at 3:12
  • 4
    Rule number one: Vulcans lie. Commented Apr 14, 2017 at 16:35

11 Answers 11


In my opinion Star Trek does a rather poor job of keeping this part of Vulcan philosophy consistent.

Proof of Vulcan verbal deception

The Vulcans are unafraid of using deception and in the Enterprise episode The Andorian Incident, they are shown to have a hidden spy base underneath a monastery. The Vulcans could have only kept that monastery a secret from the Andorians by verbal deception. Also, in the episode of Enterprise called, Carbon Creek, T'Mir claims that she cremated her subordinate, Mestral, in order to trick the vulcan high command in to letting him stay on earth for further "study".

Isn't a lie of omission, still a lie?

You can argue that lies of omission are not lies, but there is only so far you can stretch that idea without lying to yourself. The Andorians, the Vulcans' greatest enemies, would have known if the Vulcans could not tell lies, and therefore should have been able to force the Vulcans into telling the Andorians the location of the hidden spy base.

So either Vulcans can and do lie, or what is considered a lie to Vulcans is completely different from human definition.

An advanced culture would not necessarily frown on lying

The Vulcan perspective on lying may also be misguided, while it may seem simple to regard lies as both evil and the mark on an un-advanced society. In fact the opposite maybe true, that without deception a society becomes stagnant and totalitarian. Many times throughout the Star Trek series, main characters use verbal deception to avoid violence and bloodshed. I believe that narrative idea of Vulcan honesty comes from the dubious belief that all lying is wrong. Not only is it not always wrong to lie, but it is often necessary for survival as Tuvok can tell you (if he were an honest man :) ).

Maybe the TOS writers just threw the idea out there without thinking much about it.

On a Star Trek forum a user mentions that Vulcan honesty maybe in jest:

I believe the line in "Court Martial" went:

Vulcanians do not speculate.

Elsewhere, (in "The Doomsday Machine") we hear:

Vulcans never bluff.

which may, in fact, have been a bluff.

  • Additionally, in TOS: The Enterprise Incident, it's the Romulan who says something like, "isn't it true that Vulcans are incapable of lying?" Spock readily agrees and then lies the rest of the episode. The TOS writers may never have intended for "Vulcans can't lie" to be a thing at all.
    – GridAlien
    Commented Feb 19, 2020 at 18:03

From Memory Alpha:

Vulcans are known for their high degree of honesty. They are extremely reluctant to tell a lie, and indeed it is said that "Vulcans cannot lie". However, they will do so for what they perceive as logical reasons, though they rarely refer to their dishonesty as "lying." (TOS: "The Enterprise Incident"; Star Trek II: The Wrath of Khan; Star Trek VI: The Undiscovered Country) On at least one occasion, Spock lies without any apparent logical reason (and, in fact, for a reason apparently consisting of nothing more than humor), when he claims to not have seen Kirk's last orders to himself and Doctor McCoy (TOS: "The Tholian Web"). However, this may, in fact, be a result of those orders themselves, as Kirk had, in the orders, instructed Spock to follow McCoy's lead on intuitive and emotional matters, and McCoy had just refused to admit to seeing the orders.

In other words, yes and no. We could say they can lie, when logic dictates that it would serve towards the greater good. The Vulcan's would say they never lie because they don't consider bending the truth when logic calls for it as a lie.

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    There's also all the issues with Vulcan's in "Enterprise" before they return to following the ways of Surak, so they are capable of a lot of behaviors they would rather not admit to, but appear to have developed a cultural conditioning that makes it difficult.
    – Tango
    Commented Aug 10, 2011 at 20:51
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    It's not clear that Spock lied in "The Tholian Web". "Yes, you see the crisis was upon us and then passed so quickly that we ...mumble...". He didn't explicitly say that they hadn't seen the orders -- though he certainly left Kirk with that impression. Commented Jan 7, 2013 at 7:07
  • In TNG, Spock is also spearheading the underground revolutionary movement on Romulus; I don't think he would be capable of accomplishing his goals without a few lies here and there.
    – Brian S
    Commented Jan 21, 2014 at 15:32
  • I'm not sure that Spock is the best example of a Vulcan, as he is half human and deviations from purely Vulcan behavior may be attributed to his mixed heritage, no?
    – Paul
    Commented Jan 30, 2014 at 22:50

Tuvok said that he remained true to his own convictions, when questioned by Chakotay about his time as a Maquis. It is possible to be both honest and dishonest simultaneously.

  • An interesting point. A Vulcan may say what he believes to be true, whether or not it is. Commented Aug 11, 2011 at 13:35
  • Don't we (humans) also say what we believe to be true, whether it is true or not? Commented Aug 11, 2011 at 15:06
  • @Zeke: I completely believe this. (Aha! I have proven this false, by stating that I believe it when I in fact do not!)
    – Jeff
    Commented Aug 11, 2011 at 18:07
  • @Jeff: Wait, Is it possible that you only thought that you didn't believe it? In which case, it was false that it was false? Wouldn't that make it true? - (Illogic is like a bouquet of pretty flowers, that smell bad.) Commented Aug 11, 2011 at 18:28
  • @Zeke: No. I didn't believe it. You can simply believe you haven't read it, if you wish.
    – Jeff
    Commented Aug 11, 2011 at 18:52

Star Trek, The Wrath of Kahn.

KIRK: By the book! Regulation forty-six A, 'If transmissions are being monitored during battle...'

SAAVIK: '...no uncoded messages on an open channel.' ...You lied.

SPOCK: I exaggerated.

KIRK: Hours instead of days, Saavik, now we have minutes instead of hours.

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    Could you give some context?
    – AncientSwordRage
    Commented Jan 31, 2014 at 7:25
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    Context Kirk & Saavik are in a cave under a planets surface. Spock, on the Enterprise, has to leave them there after a battle with a Klingon warbird. Before leaving the exchange goes something like this Kirk: Kirk to Enterprise. Spock: Spock here. Kirk: Captain Spock, damage report. Spock: Admiral, if we go "by the book". like Lieutenant Saavik, hours could seem like days. Kirk: I read you captain. Let's have it. Spock: The situation is grave, Admiral. We won't have main power for six "days". Auxiliary power has temporarily failed. Restoration may be possible, in two "days".
    – Jaydee
    Commented Jan 31, 2014 at 13:19
  • After battle with Khan in the USS Reliant, actually, not a Klingon ship. Commented Mar 14, 2014 at 21:16
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    @AncientSwordRage Spock was "encoding" his damage report (substituting hours for days) because he (correctly) assumed Khan would be listening in. Funny thing is how he gives the cipher key ("hours seem like days") over the same monitored channel without the "superior intellect" picking up on it. Arguably not lying at all.
    – Anthony X
    Commented Oct 14, 2018 at 16:10

In S3E09 TOS.final scene: Both Bones and Spock tell a blatant lie to kirk's face that neither had seen the "last orders tape" that kirk had left behind.

  • Bones is human, though, and the question addressed Spock being only half Vulcan.
    – Jenayah
    Commented Oct 14, 2018 at 13:37
  • yes but spock has since claimed asa vulcan he is incapable of lies.
    – Q2018
    Commented Oct 14, 2018 at 14:36
  • @Q2018 When did Spock say that? Is it possible he was lying when he said he couldn't lie?
    – F1Krazy
    Commented Oct 14, 2018 at 16:13
  • @F1Krazy wouldn't that make his head explode? :D
    – Jenayah
    Commented Oct 14, 2018 at 17:20

If a lie is defined to be as an statement in contradiction to a reality ( logic in Vulcan's case ) then a statement can only be considered a lie by those who are aware of the contradiction. In the episode Gambit a Vulcan isolationist infiltrator did not tell the truth, the explanation being that their logic to force Vulcan away from Federation differed from the logic of others, so within their logic it was not a lie.

PS: All the above rests on memory of that episode from 12 years ago, if anyone has seen it more recently and can point out the mistakes in the above statement that would be great.

  • "a statement can only be considered a lie by those who are aware of the contradiction". So if a conman sells me the Sydney Opera House, he has not lied to me because I didn't know he didn't own it?
    – Jaydee
    Commented Jan 31, 2014 at 13:22

Yes, they must be. Vulcans are supposed to be 100% driven by logic and especially probability. Sometimes, the best action, or the one with the highest probability of succeeding is to lie. In poker, that's called bluffing. Spock saying that Vulcans never bluff allowed him to further increase the probability his desired result would be achieved. Now, we don't find out if it was a real bluff or not because, as expected the highest probability action taken by Spock caused the desired results.


Vulcans can and do misrepresent and in the British legal system misrepresenting is the same as lying. Perhaps the human concept of lying is different from the Vulcan concept either that or the ST writers could not keep their own canon consistent.

  • Note that Britain (as a separate state) and its legal system no longer exist in the Star Trek universe.
    – Valorum
    Commented Jan 12, 2015 at 18:00
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    One world government of Star Trek does not mean nation states no longer exists. Picard still remained French and Scotty remained Scottish. If you use the EU as a present day example, there is EU law and still national laws the latter has not disppeared....yet Another example Lt Malcolm Reed joined Starfleet and not the Royal Navy. If Britain did not exist then which nation runs the RN in the Star Trek Enterprise universe?
    – Vulcanlady
    Commented Jan 12, 2015 at 19:17
  • A single Earth Government would be likely (but not certain) to preclude having separate legal systems. Your point is well made though.
    – Valorum
    Commented Jan 12, 2015 at 19:23
  • @Valorum: US states have their own legal systems. Your logic falls apart under the federal model IMO. That being said I have no idea what the British legal system has to do with this specifically. Commented Feb 26, 2018 at 2:49

Vulcans are a peace-loving race, not the sort to impose their will or exploit others for their own gain. They might fairly be described as honest. They also inhabit a galaxy full of other races and cultures - people who see their honest character and conflate honesty with "inability to lie". Thus the characterization gets distorted and becomes part of the galactic mythos about Vulcans.


In the TOS episode, Journey To Babel, Sarek tells a bold faced lie when initially being questioned by Kirk about his whereabouts. He claims to have been privately meditating during the period of time when another Ambassador had been murdered, but later tells the truth. His illness debilitated him for hours. He lied to hide his illness, which he had also kept a secret from his wife. I believe we can categorize that as a deception by omission, compounded by the outright lie that was his alibi.

  • If you could edit in the relevant quotes that would greatly improve your answer!
    – TheLethalCarrot
    Commented Mar 23, 2019 at 15:50

Lies are what is not true. Humans see lying as "no, mom, it was the little brother who spilled the water. He should clean it up", or my personal favorite, "the window screen is broken because it's crappy. I wasnt sneaking out."

So basically, if lying is saying something you believe not to be true, then would it not be telling the truth to say something that goes along with your belief, or your logic? I see this in politics all the time. Conservatives say liberals are lying tree huggers, liberals say conservatives are lying money launderers. Both opinions are true as far as i can tell, because they are true to the opinions (logic) of the individual saying them.

Now apply this to vulcans. A vulcan thinks in facts. Their minds store information, and snobby kiss offs. So the definition of a lie to a vulcan would be saying something illogical. Ive not seen that yet. They may twist and bend the human version of truth in a way that we see as lies or deception, but really what they are doing, in their minds, is not lying at all. Its logical.

  • Your answer seems to be pure speculation. Equating lies to illogical statements does not make sense. "The check is in the mail" can be a lie while "Hobbits never cook invisible buildings correctly with ultraviolet salt" is merely illogical and nonsensical, not necessarily a lie. Commented Jan 21, 2014 at 8:49
  • It looks like your answer is quite anecdotal, do you have any more information to add? Here added references to the points you make would help back up your answer :)
    – AncientSwordRage
    Commented Jan 31, 2014 at 7:24

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