CompositionType: Informal Fallacy
All of the parts of the object O have the property P.
Should we not assume that just as the eye, hand, the foot, and in general each part of the body clearly has its own proper function, so man too has some function over and above the function of his parts?
Source: Aristotle, Nicomachean Ethics, Martin Ostwald, translator (Bobbs-Merrill, 1962), p. 16.
The human body is made up of cells, which are invisible.
Some properties are such that, if every part of a whole has the property, then the whole will toofor example, visibility. However, not all properties are like thisfor instance, invisibility. All visible objects are made up of atoms, which are too small to see. Let's call a property which distributes from all of the parts to the whole an "expansive" property, using Nelson Goodman's term. If P is an expansive property, then the argument form above is validating, by definition of what such a property is. However, if P is not expansive, then the argument form is non-validating, and any argument of that form commits the fallacy of Composition.
Sibling Fallacy: Division
The function of an organ is definable in terms of what the organ does to help the whole organism to live, however, one cannot define a function for the organism as a whole in this way. For this reason, "function" is not expansive. If it were true that human beings as a whole have a function, this would be a very different notion of function than that of the function of a human organ. So, even in this case, Aristotle's argument would commit a fallacy, though a different one, namely, Equivocation.