Chicken or the egg

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The question Which came first? - The chicken or the egg? is found earliest in Plutarch's Moralia in the section titled "Table Talk", a series of arguments based on questions posed to various people drinking around a table. It first appears in the writing in the form:

"...the problem about the egg and the hen, which of them came first, was dragged into our talk, a difficult problem which gives investigators much trouble. And Sulla my comrade said that with a small problem, as with a tool, we were rocking loose a great and heavy one, that of the creation of the world..."

Later in the writing it becomes becomes its own section entitled "Whether the hen or the egg came first."

When used in referrence to difficult problems, a chicken and egg problem is a deadlock situation where an item cannot exist until a second item exists, nor can the second item exist until the first does. For example, you cannot find a job without work experience, but you cannot get work experience without first having a job. A logical representation of the problem is:

A -> B

B -> A

The question is sometimes used as an example of the logical dilemmas of causality.

There are many different possible answers to the question "Which came first, the chicken or the egg?"

Assuming A Chicken Egg

In this case, the egg is assumed to be a chicken's egg. This is an obvious assumption since the question itself implies a link between the two.

If one assumes the egg to be a chicken egg then one must define what a chicken egg is:

If: A chicken egg will hatch a chicken

Then this allows a bypass: An animal that was not a chicken laid the chicken egg which contained the first chicken. In this case the egg came first.

If: A chicken egg is the egg that a chicken lays

Then this allows a bypass: A chicken (that hatched from a non-chicken egg) laid an egg (a chicken egg). In this case the chicken came first.

If: A chicken egg will hatch a chicken and A chicken egg is the egg that a chicken lays.

Then that results in the paradox: An animal is a chicken only if it hatched from a chicken egg, and an egg is only a chicken egg if it was laid by a chicken.

In the end, this is an error of definition, because no good definition should contain self-referrence. Nevertheless, if that error is ignored, many amusing scenarios can be considered.

Evolutionary Chicken

In this case, the egg is not assumed to be a chicken egg. In effect this changes the question to: "Which came first, a chicken or any egg".

From a pseudo science point of view this question can be answered quite easily. The egg came first because any female sex cell is called an egg.

If the egg is defined structurally as the hard shelled thing, and the chicken a feather covered animal, the answer is still simple. Evolutionary scientists believe the first hard shell egg was the amniotic egg laid around 200 million years ago, and was laid by the animal who was the link between amphibians and reptiles. The first dinosaur that we know had feathers was the Archaeopteryx, and came much later. Modern birds would not arise until 150 million years ago, descending from theropod dinosaurs.

In this case, the first chicken must have been the mutated offspring of a proto-chicken that laid the egg containing the first true chicken.

The crux of the matter is how to biologically define 'a chicken'. What level of genetic similarity or structural similarity determine whether an organism is a chicken? One can only define what was the first chicken after the fact, thus any definition of the first chicken becomes arbitrary. The question 'which came first?' ignores the complicated reality of speciation.

According to the principles of speciation, neither the chicken nor the egg came first, because speciation does not occur in simple, obvious units. In fact, evolution is about a slow transition in an overall population. What qualifies as “chicken” (ignoring the many diverse modern types of chicken) involves a wide range of genetic traits (alleles) that are not encompassed in a single individual and continue to be modified from generation to generation.

The transition from non-chicken to chicken is a gray area in which several generations are involved, and therefore which includes many many chicken-and-egg events, with no one step representing the whole. Since the result of the process is an incomplete transition into various new characteristics rather than one single blueprint, a new species, "chicken", is only identified in hindsight when the species can be obviously identified as different from its ancestral stock.

Creationist Chicken

The chicken versus egg controversy may also be considered from creationist standpoint. The creationist counterpoint to the evolutionary viewpoint could be that the first chicken was made by the Creator, and then that first chicken laid the first egg. The problem remains, however, because it could also be that the first egg was made by the creator, and the first chicken only hatched out of it afterwards.

A Question Of Whether Chickens Exist

It has been suggested that the definition of "chicken egg" could be "an egg that was laid by a chicken", creating a perpetual causual loop. Equally valid is to assume that there are, in fact, no chickens.

A Question Of Syntax

One can consider the question inside the framework of experience, making the question concrete instead of abstract: Which came first - the chicken or the egg? The chicken came first - in the sentence of the question. If the question is phrased differently, the answer is different.

Reframing The Question

It could be said that the question simply requires one to know the context. Most people thinking of the question automatically think of the timeline and it is in this manner that both the previous evolutionary theory and religious teachings contexts arise. Other potential contexts are:

Having looked through a dictionary from front to back, which came first? - the chicken or the egg?
When you walked through the supermarket, which came first? - the chicken or the egg?
When reading the menu, which came first? - the chicken or the egg?