Become a Friend of the SEP and Access PDFs

You can support the Stanford Encyclopedia of Philosophy by joining the Friends of the SEP Society. By paying modest, annual membership dues to join the Society, members will receive the following benefits: (a) download access to high quality PDF (Portable Document Format, a.k.a. Acrobat) versions of SEP entries and (b) quarterly email notifications (if you ‘opt-in’) that inform you when PDFs you've downloaded have been updated in the most recent quarterly SEP Archive.

Go to the Friends of the SEP Society Home Page
The home page for the Society is located at

Sample PDFs

Paper Size: US Letter
(8½ × 11 in)
  Paper Size: A4
(210 × 297 mm)
sample entry in US Letter format   sample entry in A4 format
Sample PDF
Entry on Turing Machines
  Sample PDF
Entry on Turing Machines

We also release our PDFs in single-column half-sheets (5½ × 8½ in)—see the Sample PDF. You might find this format especially useful for mobile devices.

Membership Levels

You can join the Friends of the SEP Society, using our secure online payment system, at one of the following levels:

For pricing information, see the section on Membership Levels at the page About the Society.