An informal fallacy of emergence, in which properties of a whole are inadmissibly inferred to from its parts.

For example:

Chloride is poisonous.
Sodium is poisonous.
Therefore, sodium chloride must also be poisonous.

Sodium chloride, better known as common salt, is an essential food ingredient, even though its atomic components are dangerous chemicals.

• Exception fallacy
• Fallacia compositionis

The fallacy of composition is counter­part to the fallacy of division. They both share the aspect that the phenomenon of emergence is ignored. It refers to a situation in which properties of parts are transferred to the whole, without checking or validating that they have not changed or disappeared in the higher systemic level.

This can also be used in situations when a resultant change in the properties of the whole is misrepresented: For example, in chemistry, ignoring that energy is released in chemical reactions and thus the energy of a compound may not be equal to the sum of that of the components.

Take, for example, a football team con­sist­ing only of the best players:

A is the best striker,
B is the best midfielder,
…
K is the best goalkeeper.
All together they are the best foot­ball team.

While it is certainly helpful to have out­stand­ing players in the team, in order to be the “best” team they must also co­oper­ate ex­cel­lently. This “inter­play” is an emergent prop­erty of a team, which the in­di­vi­dual play­ers can­not dis­play on their own, wit­hout actu­ally being part of a team.

The same could be said, for example, about an orches­tra, a band, as well as count­less other group­ings where good team­work is an im­port­ant cri­terion for success.

• Mereological fallacy
• Ecological fallacy
• Fallacy of division

• Composition on Fallacy Files