Some universities publish literature through open access presses. These are freely available to anyone, and the presses listed publish in the arts, humanities and social sciences.
The University of Sheffield has curated a list of open access presses, available here.
Access is through individual publisher websites. The link above provides a comprehensive list with access links.
Whether you have a particular book in mind or want to browse by topic, open access books from the above presses are freely and easily available, and cover the arts, humanities and social sciences.
Visit individual websites for more details. Most allow free downloads of full-text PDFs.