Another phrase for "a chicken and egg situation"

The causality dilemma or cause and effect dilemma:

• The ‘causality dilemma’ of “which came first, the chicken or the egg?” To ancient philosophers, the question about the first chicken or egg also ignited the question(s) of how life and the universe began in general.

Causality:

• "The relationship between an event (the cause) and a second event (the effect), where the second event is a consequence of the first."

(Wikipedia)

A compelling reason for seeking an alternative is that "chicken and egg" no longer carries the original meaning, or at least not in scientific circles.

The consensus in the scientific community, based on fossil evidence considered by the majority of paleontologists to be overwhelming, is that birds, including by definition chickens, evolved from dinosaurs. See e.g http://evolution.berkeley.edu/evolibrary/article/evograms_06. Dinosaurs laid eggs. Therefore the egg came first and the phrase no longer provides an example of the causality dilemma.

Replacing "egg" with "chicken's egg" might offer an alternative, but hardly an elegant one. For day-to-day use the original phrase is probably adequate; the INTENDED meaning remains clear and most will allow some poetic licence even if aware of its defficiencies.

Until someone can think of a better alternative, perhaps for formal use as per the original posting those who don't wish to risk standing corrected are stuck with something along the lines of "we have a causality dilemma"!

It's a false dilemma and most supposed circular causality problems usually are. The problem is in the question, which poses a false dichotomy, since the answer is neither.

A similar example in tech circles is the conundrum as to how one might start a social network given nobody will join if there is no network.

Like the chicken and egg problem, it is the question that is the problem, not the answer.

Social networks start with a different premise. When you understand that you will know how to start one. Chickens did not arrive on the scene as chickens and the eggs from which they did not arrive also did not come from chickens. There was no chicken day. There is no social network day. Both are realised retrospectively.