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Who really said it

I don't want to believe, I want to know

No documented author — not Carl Sagan Unknown Unattributed · circulating online since at least the mid-2010s
Disputed Rights unconfirmed

There is no Sagan source. The sentence does not appear in Cosmos, in The Demon-Haunted World, in Broca’s Brain, or in his last interview with Charlie Rose in May 1996, and Wikiquote’s sourced Sagan page does not carry it in any form. What Sagan actually wrote, on page 12 of The Demon-Haunted World, is longer, more careful and better: ‘For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring.’ The punchy version is somebody’s compression of that sentiment, and nobody has established whose.

Last verified 21 Jul 2026 · how we verify · spot an error?

For presentations

Put it on a slide

Disputed credit — copy with the correction

“I don't want to believe, I want to know” Unattributed. Not traced to Carl Sagan, who wrote instead: "For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring" — The Demon-Haunted World, 1995, p. 12.

The slide-ready mistake: crediting this to Carl Sagan. Use the credit shown above instead.

Can you use it?

We couldn’t verify where this wording comes from, so there’s no rights status to give. Safe to present as an unverified or anonymous line — just don’t assert a specific author or source.

Image direction — grounded in this quote’s real context; paste into your image tool

In context

Evoking the world of Carl Sagan — American astronomer and science communicator. Theme: "I don't want to believe, I want to know". Atmospheric and restrained, cinematic directional light, a muted period-appropriate palette, fine grain and texture. Compose with generous empty space for the quote and a small credit line. No lettering in the image itself.

Minimalist

Minimalist editorial slide for the quote "I don't want to believe, I want to know". Clean background, a single muted accent color, generous negative space, subtle paper or linen texture, no literal illustration — let the words carry it. Reserve clear space for a serif quote and a small credit line. No lettering in the image itself.

Provenance

The source

Origin
Unknown — no first appearance located
Sagan source
None in books, Cosmos or interviews
What he did write
The Demon-Haunted World (1995), ch. 1, p. 12
Nearest famous relative
Carl Jung, BBC, 22 October 1959

For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring. The Demon-Haunted World, 1995, p. 12

This is the real Sagan sentence, and the differences are worth noticing. He says ‘for me’ — it is a preference, not a rule for you. He says ‘grasp the Universe as it really is,’ which is harder work than ‘know.’ And he concedes, in the same breath, that the delusion really is satisfying and reassuring. The internet version wins the argument; Sagan was too honest to.

How we traced it

  • Start with the negative evidence, because it is unusually clean. Sagan’s books are indexed and searchable, Cosmos has a published script, and his final interview has a full transcript. None contains the sentence. Wikiquote’s Sagan page — which does list his sourced lines by chapter and page — has no entry for it either the sourced list ↗.
  • What Sagan does have is a genuine, page-numbered sentence saying the same thing at greater length, in chapter 1 of The Demon-Haunted World (1995), p. 12. Nearby on the same page: ‘If we long to believe that the stars rise and set for us, that we are the reason there is a Universe, does science do us a disservice in deflating our conceits?’ That is the register the aphorism is compressing.
  • The shape of the aphorism — believe versus know, in two beats — has a famous owner, and it is not Sagan. Asked on the BBC’s Face to Face on 22 October 1959 whether he believed in God, Carl Jung paused and said: ‘I know. I don’t need to believe. I know.’ Same two words, opposite conclusion, and a different Carl the 1959 interview ↗.
  • One claimant exists: the Brazilian-born author Paulo Bittencourt says on his own author blog that he wrote the sentence, in Liberated from Religion. We record the claim and do not adopt it — it is self-asserted, and we have not seen a dated printing that predates the line’s circulation online the claim ↗.

Rights here are genuinely tangled, so tread carefully. The aphorism itself has no established author, which means there is nobody to license it from and nobody who can clear it — unknown authorship is not the same as public domain. The Sagan sentence quoted above is from a 1995 book and is in copyright to his estate; quote it briefly, with the page. Jung’s 1959 BBC answer is likewise in copyright, in the recording and in the transcripts. This is not legal advice.

Fact-check

The attribution problem

This one fails in the quietest way a quotation can: nobody made anything up, someone just tightened a real sentence until it fitted on a poster, and the poster kept the name.

Not Carl Sagan no source of any kind

Absent from Cosmos, The Demon-Haunted World, Broca’s Brain, Pale Blue Dot and the 1996 Charlie Rose interview, and absent from Wikiquote’s sourced list. Every site carrying it — and there are hundreds — cites another quote site.

Carl Sagan, 1995 sourced to a page

‘For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring.’ The Demon-Haunted World, chapter 1, ‘The Most Precious Thing,’ p. 12. Same idea, with the concession left in.

Carl Jung, 1959 where the shape comes from

On the BBC’s Face to Face, 22 October 1959, John Freeman asked Jung whether he believed in God. Jung hesitated: ‘I know. I don’t need to believe. I know.’ It caused a national row. Two famous Carls, the same two verbs, opposite conclusions — a good recipe for a quotation losing its owner.

Paulo Bittencourt unverified

The author of Liberated from Religion states on his own author blog that the sentence is his and that Sagan never wrote it. The second half is right. The first half is self-asserted and we have not been able to verify a dated first printing, so we leave the authorship open.

No Sagan source exists. He wrote a longer, better version on p. 12 of The Demon-Haunted World; the ‘believe / know’ shape belongs to Carl Jung on the BBC in 1959 the sourced list ↗.

Context

Why it resonates

Eight words, two verbs, and a whole worldview. It is the shortest possible way to say that comfort is not a reason, which is why it ends up on placards, in bios and under photographs of nebulae — and why it needed a famous sceptic’s signature.

The loss in compression is real, though. Sagan always conceded that the delusion is satisfying; the slogan does not, which makes it sound like contempt rather than the hard-won preference he described.

Sagan always admitted the delusion was comforting. The slogan does not.

Where people say it comes from — and what is there instead

Cosmos (1980): not in the series or the book.

The Demon-Haunted World (1995): not present — but p. 12 carries the genuine, fuller version.

The Charlie Rose interview, 27 May 1996: full transcript available; the words are not in it.

Carl Jung, BBC Face to Face, 22 October 1959: ‘I know. I don’t need to believe. I know.’

Paulo Bittencourt, Liberated from Religion: claimed by its author, unverified here.

Explore

Filed under

More provenance-checked quotes on the same theme, each with its reuse status.

Doubt Truth

Go further

Dig deeper

Trusted places to keep pulling the thread — primary archives, fact-checks, and scholarship. We show how we used each one before you leave.

Carl Sagan — sourced quotations, by book and pageen.wikiquote.org

The community-sourced list. Useful mainly for what is not in it — this line appears nowhere, in any section.
Did Carl Sagan say ‘I don’t want to believe, I want to know’?quora.com

The question that keeps getting asked, and the answers that keep failing to produce a source.
Face to Face: the BBC’s 1959 interview with Carl Jungjungiananalysts.org.uk

Background on the broadcast of 22 October 1959, where Jung told John Freeman ‘I don’t need to believe. I know.’
Carl Sagan’s last interview, May 1996 — full transcriptspeakola.com

The conversation with Charlie Rose the line is sometimes said to come from. Search it: the words are not there.

Popularly credited author

Why it gets pinned on Sagan

Carl Sagan

1934–1996 · American astronomer and science communicator

Carl Sagan spent the last years of his life arguing, in The Demon-Haunted World and on television, that wanting something to be true is not evidence that it is — so a slogan that says exactly that in eight words is going to end up with his name on it. He is the patron saint of a certain kind of hopeful scepticism, and hopeful sceptics need a motto. The irony is that his own version is better and is fully sourced to a page number, and almost nobody quotes it.

For writers & researchers

Cite this

Primary source — Chicago

Unattributed aphorism; no source in the works of Carl Sagan. Compare Sagan, Carl. The Demon-Haunted World: Science as a Candle in the Dark. New York: Random House, 1995, ch. 1, p. 12; and Carl Jung, BBC Face to Face, 22 October 1959.

MLA (9th ed.)

“I don’t want to believe, I want to know.” Unattributed; commonly misattributed to Carl Sagan.

APA (7th ed.)

I don’t want to believe, I want to know. (n.d.). Unattributed aphorism [commonly misattributed to Carl Sagan].

This verification page

Quotle.info. “Who really said ‘I don’t want to believe, I want to know’?” Last verified 21 Jul 2026. https://quotle.info/who-said/i-dont-want-to-believe-i-want-to-know

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