This is a pretty good summary of the philosophical difference between Thomas's and Breyer's view of copyright.
I'll add that Thomas points out that if Breyer wants to talk about "thin" copyright, he should have discussed it within the copyrightability context, not skirting and discussing it in the "fair use" segment. If Breyer does so, Thomas argues, Breyer would find that "thin" copyright is still copyright, and Google will have no argument left to support fair use. All the remaining facts (such as competition, loss royalty, etc.) would support non-fair use.
I'll add that Thomas points out that if Breyer wants to talk about "thin" copyright, he should have discussed it within the copyrightability context, not skirting and discussing it in the "fair use" segment. If Breyer does so, Thomas argues, Breyer would find that "thin" copyright is still copyright, and Google will have no argument left to support fair use. All the remaining facts (such as competition, loss royalty, etc.) would support non-fair use.