Most of our library databases search beyond our own holdings and subscriptions. However, Ebsco Discovery Service (the search box on the library home page) defaults to searching only our own collections. See this example of a search, where it found 382 hits:
To search beyond DePauw, X out that filter. This will search journal citations in lots of our databases, and will search books owned by PALNI (Private Academic Libraries Network of Indiana). You can see the increased number of hits (from 382 to 1708).
To find books beyond DePauw and PALNI holdings, try WorldCat Discovery. Our access to this will be going away soon, but it's the best current option available.