Pierre Bayard has compelling argument for discussing books that you’ve never touched in a Guardian Op-Ed.
I have often found myself in the delicate situation of having to express my thoughts on books I haven’t read. Because I teach literature at university level, there is, in fact, no way to avoid commenting on books that I haven’t even opened. It’s true that this is also the case for the majority of my students, but if even one of them has read the text I’m discussing, there is a risk that at any moment my class will be disrupted and I will find myself humiliated.
Bayard does not exactly say one should lie about the books they’ve read, but he does offer that we can no many thing about books unread:
Between a book we’ve read closely and a book we’ve never even heard of, there is a whole range of gradations that deserve our attention. In the case of books we have supposedly read, we must consider just what is meant by reading, a term that can refer to a variety of practices. Conversely, many books that by all appearances we haven’t read exert an influence on us nevertheless, as their reputations spread through society. Reading is not a simple, seamless process; it has fault lines, deficiencies and approximations.