The Stanford Encyclopedia of Philosophy (SEP), an open-access dynamic reference work, invites you to join 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. The SEP has a comprehensive PDF Library of its entries, and we generate new PDFs after each quarterly SEP Archive for those entries that have been published or revised during the previous 3 months. For more information, read About the Society.

Paper Size: US Letter (8½ × 11 in)		Paper Size: A4 (210 × 297 mm)
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.

Members may get other member benefits as these become available.

Membership Levels

For a complete description, see About the Society→Membership Levels. In summary, you can join the Friends of the SEP Society, using our secure online payment system, at one of the following levels:

• Associate Member: Membership dues of $10/year. Associate members may download any of the PDF versions in the PDF Library but are limited to downloading a maximum of 5 different entries per day.
• Student Member: Membership dues of $5/year. Student members have the same privileges as Associate Members.
• Professional Member: Membership dues of $25/year. Professional members may download any of the PDF versions in the PDF Library, with no daily limits on the number of different entries that can be downloaded each day.

For purposes of security, the Friends of the SEP Society office does not store credit card information. Please do not send your credit card information by email, phone, or letter. To become a member, you must follow the link to join the Society and complete the secure online payment process.

Acknowledgments

The SEP would like to thank the William and Flora Hewlett Foundation for providing most of the funds used to build the Friends of the SEP Society website. We'd also like to thank Paul Daniell for the programming excellence he demonstrated in developing this site.