Here's two examples of what I'm talking about


An ideal citizen would be smart, ethical and politically engaged.

However, what usually happens in reality is this:

  • If they're smart and politically engaged, they're not ethical.
  • If they're ethical and politically engaged, they're not smart.
  • If they're smart and ethical, they're not politically engaged.


The boss wants the work to be top-quality, done quickly and low-cost.

The tired worker tries to explain that:

  • If it's done quickly and low-cost, it won't be top-quality.
  • If it's top-quality and low-cost, it won't be done quickly.
  • If it's top-quality and done quickly, it won't be low-cost.

Basically, it's "you can't have your cake and eat it too", but I wonder if there's a shorter name for it, something like "So-and-so's Clause".


  • In programming, there are several of these, referred to as "Iron Triangles". One should minimize run time, resource usage and complexity. Hardware should be fast, cheap and reliable.... Fixing either of the two generally makes the third explode. – user9166 Oct 24 '19 at 16:20
  • (In a more classical spirit they generally fall into one of the two classical triads: Cardinal, Fixed and Mutable triads or their counterpoints in Real, Imaginary and Symbolic processes. For instance time is imaginary, resources are real and complexity is symbolic -- speed is mutable (a form of change), money is fixed (derived from matter) and quality is cardinal (a kind of moral goal).) – user9166 Oct 24 '19 at 16:26
  • @jobermark Interesting example. Where does the concept of the two classical triads come from? If I remember correctly RIS is originally a Lacanian analysis concept, but I'm not familiar with CFM. – user62099 Oct 24 '19 at 18:17
  • CFM is part of Hermeticism. One only currently encounters it in Jungian pyschology, Alchemical metaphors and Astrology. RIS is "originally" from Lacan only in that he revived it. The R, I and S are the "complements" M, C and F respectively. – user9166 Oct 25 '19 at 21:42
  • i.e. Symbols are mental and 'moral'/mutable and cardinal, Images are mental and 'given'/mutable and fixed. Reality is cardinal and fixed -- it feels like an outside force you have to obey, and you have no choice. – user9166 Oct 25 '19 at 21:51

Welcome, user62099

The usual term is an 'inconsistent triad' :

an inconsistent triad ... a collection of propositions, any two of which are compatible with each another but which, when viewed together in a threesome, form a contradiction.

(Albert Weale, 'Rationing Health Care: A Logical Solution to an Inconsistent Triad', British Medical Journal, Vol. 316, No. 7129 (Feb. 7, 1998), p. 410.)

Another example of the use of this term:

K. W. Rankin, 'Is the Third Man Argument an Inconsistent Triad?', The Philosophical Quarterly (1950-), Vol. 20, No. 81 (Oct., 1970), pp. 378-380. ('The Third Man' relates - perhaps you know this already - to a problem in Plato.)

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  • Brilliant! Thank you for the citations. – user62099 Oct 24 '19 at 14:39

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