Fallacy of Composition
An informal fallacy of emergence, in which properties of a whole are inadmissibly inferred to from its parts.
Chloride is poisonous. Sodium is poisonous. Therefore, sodium chloride is also 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.
Note: making a clear distinction between emergent and resultant properties can be difficult and is often up for debate. This debate is especially controversial in sciences like Physics and Chemistry. However, the fact that drawing a clear line is difficult does not imply that such a distinction does not exist (☞ sorites fallacy).
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.
- Ecological fallacy
- Mereological fallacy
- Composition on Fallacy Files