LR Bible 2015, page 474, ex. 4

[DlarehAtsok]

"Philosopher: Scientist talk about the pursuit of truth, but, like most people ..." Answer Key (page 479) claims that answer choice (A) makes a composition error. However, to me it looks like more of a over-generalization. In effect, would you mind to help me on how to distinct between these two (over-generalization and composition)?

[Jonathan Evans]

Hi, Dlareh,

Good question. In effect, flaws of composition are related to flaws of overgeneralization, except that composition flaws replace constituent members or parts of something with the whole. In a flaw of composition, the whole is qualitatively different from its parts whereas in a flaw of overgeneralization, the parts and larger assembly of these parts are quantitatively different but not necessarily qualitatively different. You generalize about more of something than is warranted but you haven't switched into something else entirely. In this question, the Philosopher shifts from individual scientists to the "scientific community." In a similar manner, you may imagine that individual church members may be not at all charitable and concerned with caring the poor. However, the church as a whole may be very charitable or do a lot to aid the poor.

Please let me know if this clears up your question or if I may provide further explanation.

[DlarehAtsok]

In fact that is how I understood the difference between over-generalization and composition also. However, while I understand that scientific community is a composition of scientists, I am confused why Answer Key (page 479) claims that answer choice (A) makes a composition error. (A) deals with "each and every scientist", so it must be an over-generalization (only quantitative change) not a composition, right?

[Jonathan Evans]

It might be best to think of it thus: over generalization is a kind of informal logical flaw that is in some cases exemplified in composition errors. Answer choice A is both an example of over generalization and of composition. If A had addressed only "many scientists" and not "each and every scientist," it would have been only an error of generalization and not of composition. Answer choice B, the correct response, describes an error of composition that is not an example of over generalization, in the strict sense.