Fallacies of Grammatical Analogy

Include composition and division. Arguments that commit this fallacies are grammatically analogous to other arguments that are good in every respect. They may appear good yet bad.

21. Composition
Committed when the conclusion of an argument depends on the erroneous tranference of an attribute from parts of something onto the whole. This fallacy occurs when it is argued that because the parts have a certain attribute, it follows that the whole has that attribute too and the situation is such that attribute in question cannot be legitimately transferred from parts to whole.

Example:
Maria like anchovies. She also likes chocolate ice cream. Therefore, it is certain that she would like a chocolate sundae topped with anchovies.

Sodium and Chlorine, the atomic component of salt, are deadly poisons. Therefore, salt is a deadly poison.

22. Division
It is the exact reverse as composition. Division goes from whole to parts.The fallacy is committed when the conclusion of an argument depends on the erroneous tranference of an attribute from whole (or class) onto its parts (or members).

Example:
Salt is nonpoisonous compund. Therefore, its component element, sodium and chlorine, are nonpoisonous.

The Royal Society is over 300 years old. Prefessor Thompson is a member of the Royal Society. Therefore, Professor Thompson is over 300 years old.