The fallacy of division is a logical error that occurs when it is assumed that what is true for the whole must also be true for its parts. In other words, it mistakenly attributes the characteristics or properties of an entire group, object, or entity to each individual part without sufficient justification. This fallacy can arise in many contexts, such as assuming all members of a group share a group's characteristic or that parts of a system exhibit the properties of the whole system. For example, if a house is said to be green, assuming that the front door of the house is also green would be committing this fallacy. Similarly, if a university is ranked as the best overall, concluding that every faculty within the university is the best in its field is a fallacy of division. Another example is assuming neurons can think individually because the brain, which they compose, can think. This fallacy is the converse of the fallacy of composition, which wrongly attributes the properties of parts to the whole. The fallacy of division often stems from overgeneralization or confusing collective properties with distributive ones. In summary, the fallacy of division arises when the false assumption is made that properties of a whole must apply equally to its parts, leading to incorrect conclusions in reasoning.
