The title says it all. I will include an example sentence to contextualise how I want to use this word:

Cooperation, reciprocity and trust are the _____ to human prosperity—not selfishness.

Of course I can reframe the sentence and just simply say “are crucial to” or “are pivotal to”, but I really want a plural noun that is similar to fulcrum to designate more than one thing as being pivotal to give the sentence extra “punch”.

I checked and found that ‘fulcra’ is the plural noun of fulcrum, but it just sounds a little awkward for my liking and I could not find sufficient examples of it used in sentences.

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    This is not a matter of words; this is a matter of metaphors. If you use a teeter-totter/balance scale metaphor, there can only be two weights and one fulcrum. A balance with two fulcrums is not a balance. You could use a door metaphor and call them the keys to success. Or you could say they're the basic ingredients and use a food metaphor. Just matching words by perceived meaning leads to mixed metaphors. Aug 27, 2019 at 20:26
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    You could also use a building metaphor, pillars, which is often used with prosperity: Cooperation, reciprocity and trust are the pillars of human prosperity—not selfishness. Aug 27, 2019 at 20:47
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    Your question is based on a false premise. The plural of fulcrum is also fulcrums. In fact, Merriam-Webster lists it in the first position, so it's likely more common. Aug 28, 2019 at 0:22
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    Accepting @John's point - "keys" seems the obvious metaphor, or you could say they were the criteria "to human prosperity". Or you could say they were critical to "human prosperity".
    – WS2
    Aug 28, 2019 at 8:35
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    @JohnLawler that'd make a great answer
    – Kat
    Aug 28, 2019 at 15:36

9 Answers 9



something that is essential, indispensable, or basic

(source: Dictionary.com)

The sentence would become:

Cooperation, reciprocity and trust are the cornerstones of human prosperity—not selfishness

  • 1
    I think this is the one! I always struggle to distinguish it from keystone.
    – R.Cunliffe
    Aug 27, 2019 at 20:36
  • @R.Cunliffe - keystones are fairly vital, too. Aug 27, 2019 at 20:46
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    It may sound a bit odd that there are only three cornerstones rather than four, though. Aug 28, 2019 at 12:37
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    @marcellothearcane Keystones are exactly as vital as all the other stones.
    – Strawberry
    Aug 28, 2019 at 17:09
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    @FedericoPoloni - All rectangular buildings have four corner (space) stones. What would weird is if it had four cornerstones "carved with the date and laid with appropriate ceremonies." – dictionary.com . There's only up to one keystone per arch, and one cornerstone per building. Using either to metaphorically refer to more than one thing is already pushing it.
    – Mazura
    Aug 28, 2019 at 22:50

I think a very simple word works best here, namely keys:

2 b : an instrumental or deciding factor
// the key to her success

(source: Merriam-Webster)

It will be understood by virtually everybody, unlike fulcrum which I actually had to look up...


pillars OED

A fact or principle which is a main support or basis of something.

As in:

1920 F. S. Fitzgerald This Side of Paradise There had been a time when his own Celtic traits were pillars of his personal philosophy.

... the pillars to human prosperity

A pillar can be someone or thing that is considered a foundational or supportive. Someone indispensable to your company might be considered a pillar to the organization, a loved one a/the pillar of your life.

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    The thing I like with "pillars" is that you cant remove too many of them without "it" collapsing. Aug 29, 2019 at 8:16

Linchpins also comes to mind. From Merriam Webster Dictionary

One that serves to hold together parts or elements that exist or function as a unit.


Foundations would work (and is almost a synonym of cornerstones). "Foundations of human prosperity" results in a few literal google hits.

(If you allowed verbs I would actually opt for hinges which preserves your mental image of "pivoting": Human prosperity hinges on cooperation, reciprocity and trust. A nice side benefit is that you can have multiple hinges, as opposed to only a single fulcrum ;-).)

Because this answer was deemed too short by a reviewer I'll mention the obvious reasons to give this answer: Like cornerstone, foundation denotes a base on which another thing (here: human prosperity) rests and without which it cannot be established, which makes it a good term for a sine qua non, which is how I understand the question. The google hits are a good enough reference for me — they show that the literal word combination is indeed used, at least occasionally.

  • Or in adjective form: "Cooperation, reciprocity and trust are foundational to human prosperity—not selfishness."
    – GEdgar
    Aug 28, 2019 at 12:49
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    @GEdgar I'd also prefer adjectives, but the OP explicitly wants to use nouns. Aug 28, 2019 at 12:53

Consider basis

Cooperation, reciprocity and trust are the basis of human prosperity—not selfishness.

EDIT: Per comments below, bases is truly the correct term... but basis is arguably usable because the three (cooperation, reciprocity, trust) can be considered together as one.

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    Someone will probably point out that the plural is 'bases'. Like you, I'd use 'are the basis' (and I feel argumentative, for once). Aug 28, 2019 at 19:14
  • Maybe you were thinking of "basics".
    – Mr Lister
    Aug 29, 2019 at 13:13
  • @MrLister no, basis (or bases, as Mr. Ashworth astutely pointed out)
    – kmiklas
    Aug 29, 2019 at 13:31
  • Perhaps explicitly stating together the word basis makes sense: Cooperation, reciprocity and trust together form the **basis** of human prosperity—not selfishness. One could argue that this is assumed.
    – kmiklas
    Aug 29, 2019 at 13:50

These are sometimes called gating items or events.

See this answer from Lawrence:

This is called a gating question. Think of the question as a gate to the rest of the test. If you don't get past the gate, the rest of the test doesn't matter.

See this answer from me:

And the term I've heard used quite a bit: gating criteria, which is used in project management to mean a condition required to pass on to the next phase.

See this question from Thomas Weller:

In project management for software development our bosses have introduced quality gates. The idea is to reach a certain level of quality before the project can continue in the next phase.

Now, the criteria for that are called gating criteria and I wonder whether gating is a good choice. Looking up the Oxford dictionary, there's no such word.

  • 1
    I like this term. Can think of many instances in which it can be used effectively. Thanks for introducing me to a new word for several contexts.
    – R.Cunliffe
    Aug 27, 2019 at 20:35
  • The only problem with this word is that it is not likely to be generally understood.
    – TonyK
    Aug 28, 2019 at 12:12

The way to provide leverage in several steps is to use gears or cogs.

Cooperation, reciprocity and trust are the cogs of human prosperity—not selfishness.

Also, another common analogy would be links in a chain but I think you are trying to emphasize the leverage perspective so the above would be preferential in my opinion.



Although it is a plural form, it does sound a little clunky. If 'the' in the sentence is removed then the use of intrinsic is fine but it loses the OP's requirement for stress on multiples.

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