There is a word that describes one thing is because of the other thing and vice-versa ie. the ocean is blue because the sky is blue, the sky is blue because the ocean is blue. Can anyone tell me what it is?

The word -------- means: the sky is blue because the ocean is blue, the ocean is blue because the sky is blue.

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    'The sky is blue' because the blue wavelengths of the 'white' light of the sun are preferentially scattered. But a two-way implication A <==> B means 'A implies and is implied by B'. – Edwin Ashworth Aug 29 '16 at 18:38
  • i know - but this is often times how it's described or used as an example of this word. the content may not be factual but the meaning behind it is what this word means, "one thing is because of the other thing. the other thing is because of that thing..." – Sura Simpson Aug 29 '16 at 18:41
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    This sounds like circular reasoning. – vpn Aug 29 '16 at 18:42
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    I'm afraid your example is not very helpful. Notwithstanding the sad optics that sob in a corner, the example doesn't really show the reasoning you want to describe. As such there would be a lot of guesswork involved when looking for the word. – Helmar Aug 29 '16 at 18:44
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    Based on your example, the correct mathematical term may be transitive relation en.wikipedia.org/wiki/Transitive_relation – Othya Aug 29 '16 at 18:44

There is no English word which means what you explain. You would need to use more than one word, and there is no good phrase that fits every context you might want to use that idea in.

"Mutual" can be an adverb or an adjective describing two things having something in common. "Mutual causality" could mean one thing causes the other and vice versa, for example.

"Reciprocity" is a noun meaning when one thing does something for another thing, that thing responds in kind. The verb form is "reciprocate". If the ocean makes the sky blue precisely in reaction or response to the sky making the ocean blue, you could say the ocean is "reciprocating".

"Circular logic" is a noun phrase. It describes a bad way of thinking which ends at the same place it began. An example is, "All apples are red; therefore all apples are red." In this example, stating that "all apples are red" in the attempt to justify the statement that, "All apples are red," is silly because it doesn't offer any additional explanation. You're using the idea itself to try to explain the idea, essentially going in circles.

Do any of these things sound familiar to you?

  • it isn't either of those. and saying the ocean is blue because the sky is blue and vice-versa, is not the same as saying "all apples are red, therefore all apples are red" if that's how you are interpreting my example i can understand why you might not know what the word is that i am asking about. and its not reciprocity. its a word that is not often used. hence, it not being on the tip of my tongue nor in the recesses of my brain :) – Sura Simpson Aug 29 '16 at 18:55
  • There is no single word in the English language which describes mutual causation. If you're confident there's a single word that fits your meaning perfectly, you need to come up with a better example. – R Mac Aug 29 '16 at 19:03

For the single word, two might satisfy your description. First, and perhaps best by reason of its frequency and conformance with the meaning you described, is 'interdependent' or 'interdependence':

interdependent, adj. or interdependence, n.
adj.: Dependent each upon the other; mutually dependent.
n.: The fact or condition of depending each upon the other; mutual dependence.

(Definitions from OED Online.)

Another possibility, although much less common and perhaps suited only to technical uses (for example, in systems theory), is 'interdetermination':

interdetermination, n.
cause and effect operating among several factors : multiple causation.

(Definition from Merriam Webster Unabridged.)

A thorough and agreed upon definition of 'interdetermination' is not easy to come by. The definition varies with the specialized field of application. Sir Joseph Larmor, for example, an Irish physicist and mathematician, used the term in a theoretical physics treatise titled "Questions in Physical Interdetermination" (1920, in the Proceedings of the International Congress of Mathematicians). For nontechnical audiences, the best description of his meaning I could find in the paper was this:

Such complete interdetermination is a very remarkable mode of relation. It involves that knowledge of change in any small part of a system determines the change throughout: that each part is in a sense the cause of the whole. The familiar relation of cause and effect has thus vanished, along with all its metaphysical perplexities: every part of the set of concurrent events is now the determining cause of all the remainder.

Perhaps more usefully and certainly more recently, in a book titled Mutual Causality in Buddhism and General Systems Theory (Joanna Macy, SUNY Press, 1991), the term is used in a general sense:

The expressions mutual causality, reciprocal causality, dependent co-arising, interdependence, and interdetermination are, for the purposes of this book, taken as roughly equivalent in meaning.

Later in the same work, a definition of 'interdetermination' is quoted from Ervin Laszlo (originator of Systems Philosophy as a formal discipline):

Now interdetermination implies a dual relation between cause and effect...A determines B and B determines A...The reciprocity of the causality connecting A and B consists in this: as a result of a cause emanating from A, B manifests a modification in its relations to A, which modification itself can be regarded as the cause produced by B, acting on A, and resulting from the effect of the primal cause (A acting on B).


A concept that may be related to what you’re looking for is symbiosis:

Cambridge English Dictionary:

    • a close connection between different types of organisms in which they live together and benefit from each other
    • a relationship between two types of animal or plant in which each provides for the other the conditions necessary for its continued existence

Collins English Dictionary:

    • Symbiosis is any relationship between different things, people, or groups that benefits all the things or people concerned.
    • a similar relationship of mutual interdependence
    • A symbiotic relationship is one in which organisms, people, or things exist together in a way that benefits them all.
    • ...a symbiosis between monarch and church.
    • ...fungi that have a symbiotic relationship with the trees of these northwestern forests.
        Experts suspect that a symbiotic relationship between the fungus and the tree has been unbalanced by a gradual drying of soil in recent years.
    • This symbiotic relationship between industry and university has paid dividends.

Oxford English Dictionaries:

    Interaction between two different organisms living in close physical association, typically to the advantage of both.


It’s hard to find a good single-word answer.  A two-word noun phrase that seems to come close to what you want is causal loop.  (Note that the first word is “causal”, the adjective form of “cause”, and not “casual”.)

From Wikipedia:

A causal loop in the context of time travel or the causal structure of spacetime, is a sequence of events (actions, information, objects, people) in which an event is among the causes of another event, which in turn is among the causes of the first-mentioned event.  Such causally-looped events then exist in spacetime, but their origin cannot be determined.

A similar concept is the chicken and egg situation:

a situation in which it is impossible to say which of two things existed first and which caused the other one
    — Cambridge English Dictionary

… because, of course, the chicken exists because it hatched from an egg, and the egg exists because it was laid by a chicken.

A more tenuously related concept is the self-fulfilling prophecy:

A self-fulfilling prophecy is a prediction that directly or indirectly causes itself to become true, by the very terms of the prophecy itself, due to positive feedback between belief and behavior.
    — Wikipedia

The Oxford Handbook of Analytical Sociology gives this example (paraphrased):

  • People fear that the banks are going to run out of money, so they withdraw their funds.
  • Because people have withdrawn their accounts, the banks run out of money.

Again, in a sense, each thing happens because of the other one.


Are you talking about the word "hence" which conveys an 'if/then' relation to two things. This is from Merriam-Webster: link hence: play adverb \ˈhen(t)s\ Popularity: Top 20% of words Simple Definition of hence : for this reason : later than the present time

So it would be used like this:

The ice caps are melting, hence the rise in ocean levels.

There is a storm coming, hence the dark skies and gusty winds.

Or, if it was true, your example "The ocean is blue, hence the sky is blue."

  • hence? no. but thanks. – Sura Simpson Aug 29 '16 at 19:05
  • I don't understand the reason for the down votes. This answer fits the description. I feel like it's a good answer and it very well could have been the word Sura was looking for based on what little information was given. Could someone explain? – Joshua A Sep 2 '16 at 19:07
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    @JoshuaA, "hence" only implies a one-way relationship. Like you say in your description, if x, then y. It says nothing about if y, then x. I believe that the OP is looking for a word that implies both relationships simultaneously. That's the reason that I down-voted, at least. – vpn Sep 9 '16 at 2:52

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