structure for 'Reason'    |     alphabetical list of themes    |     unexpand these ideas

2. Reason / F. Fallacies / 5. Fallacy of Composition

[attributing the properties of members to the set as a whole]

5 ideas
'If each is small, so too are all' is in one way false, for the whole composed of all is not small [Aristotle]
     Full Idea: The sophistical argument 'if each is small, so too are all' is in one way true and in another false. For the whole composed of all the parts is not small, but it is composed of small parts.
     From: Aristotle (Politics [c.332 BCE], 1307b36)
     A reaction: If neurons can't think, then brains can't think.
If the parts of the universe are subject to the law of nature, the whole universe must also be subject to it [Cicero]
     Full Idea: If the parts of the universe are subject to the law of nature, then the universe itself must be subject to this law.
     From: M. Tullius Cicero (On the Nature of the Gods ('De natura deorum') [c.44 BCE], II.86)
The fallacy of composition is the assumption that what is true of the parts is true of the whole [Mautner]
     Full Idea: The fallacy of composition is an inference relying on the invalid principle that whatever is true of every part is also true of the whole; thus, we cannot assume that because the members of a committee are rational, that the committee as a whole is.
     From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], p.102)
     A reaction: This is a very common and very significant fallacy, which is perpetrated by major philosophers like Aristotle (Idea 31), unlike most of the other informal fallacies.
Don't assume that a thing has all the properties of its parts [Macdonald,C]
     Full Idea: The fallacy of composition makes the erroneous assumption that every property of the things that constitute a thing is a property of the thing as well. But every large object is constituted by small parts, and every red object by colourless parts.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.5)
     A reaction: There are nice questions here like 'If you add lots of smallness together, why don't you get extreme smallness?' Colours always make bad examples in such cases (see Idea 5456). Distinctions are needed here (e.g. Idea 7007).
Formally, composition and division fallacies occur in mereology [Hanna]
     Full Idea: Informal fallacies of composition and division go over into formal fallacies of mereological logic.
     From: Robert Hanna (Rationality and Logic [2006], 7.3)