In German, there is a phrase like "dangerous semi-knowledge" gefährliches Halbwissen. Wiktionary definition:

a degree of superficial knowledge that becomes dangerous or deceptive because it has one trust one’s own amateurish judgment

I can't think of any equivalent in English. Any ideas?

  • Dangerous superficial knowledge!
    – user 66974
    Sep 21 at 8:13
  • That's one of the senses of "common knowledge" -- "facts" that aren't true but are commonly accepted by far too many people. Sep 21 at 19:45
  • 1
    I have deleted my answer after posting on SE German Language. It turns out that "Halbwahrheit" exists, and is the obvious equivalent of "half-truth", whereas there is no equivalent single English noun to "Halbwissen".
    – David
    Sep 21 at 21:08

1 Answer 1


In English, we'd say that someone who behaves in that way exhibits the Dunning-Kruger effect: from Wikipedia, "In popular culture ... a claim about general overconfidence of people with low intelligence", although as the article points out, the original paper discussed competence in a professional environment rather than generally.

We might also say that they "know just enough to be dangerous", although that isn't really a stock phrase.

There's also a well-known quotation:

A little Learning is a dangerous thing

Alexander Pope, An Essay on Criticism (1711).

  • 2
    Pope's original quote is probably better known as: a little knowledge is a dangerous thing
    – Mari-Lou A
    Sep 21 at 10:23
  • 1
    @Mari-Lou A There doesn't seem to be a great difference in their idiomaticity. I learned the 'learning' variant. Sep 21 at 10:28
  • 1
    @EdwinAshworth that's probably because you were born in an age where trains ran on steam... :P P.S I'm not far behind.
    – Mari-Lou A
    Sep 21 at 10:33
  • 1
    @Mari-Lou A You're a tender? Sep 21 at 11:01
  • 1
    @EdwinAshworth Very funny, yes. I might be described as looking like a tank :)
    – Mari-Lou A
    Sep 21 at 11:13

Not the answer you're looking for? Browse other questions tagged or ask your own question.