Privacy Policy

What we collect directly

This is a static site. There are no accounts, no comments and no forms. Reading a page requires no personal information from you whatsoever.

If you choose to write to [email protected] or [email protected], we receive your address and the contents of your message, and we use them only to reply and, where relevant, to revise an entry.

Server logs

Like every web server, ours records access logs: IP address, time, requested URL, referring page and browser identifier. These logs are used to diagnose faults, identify abuse and keep the site secure. They are retained for no longer than 30 days and then rotated away.

Logs are not shared with third parties and are not used to build personal profiles.

Advertising and Google AdSense

This site carries advertising through Google AdSense to cover domain and hosting costs.

Google is a third-party advertising vendor. As part of serving ads, Google uses cookies — including the DoubleClick DART cookie — to serve advertising based on your prior visits to this site and to other sites on the internet.

You can opt out of personalised advertising through Google's Ads Settings page, and you can opt out of some third-party vendors' use of cookies for personalised advertising at aboutads.info. Opting out does not remove advertising; it makes the advertising no longer based on your browsing history.

Third-party ad networks may also use web beacons, pixels or similar technologies to count impressions and measure performance. We do not control the contents or the use of those third-party cookies; they are governed by the privacy policies of their respective vendors.

European Economic Area, UK and Switzerland (GDPR)

If you are in the European Economic Area, the United Kingdom or Switzerland, you have the following rights under the General Data Protection Regulation and equivalent legislation:

• Access: to be told what data relating to you we hold.
• Rectification: to have inaccurate data corrected.
• Erasure: to have data relating to you deleted, for example an email exchange you initiated.
• Restriction and objection: to have certain processing stopped.
• Portability: to receive the data you supplied in a structured, commonly used format.
• Withdrawal of consent: at any time, where processing was based on consent.

Legal bases and international transfers

Our legal basis for processing server logs is legitimate interest — keeping a working, secure site available. Our legal basis for handling correspondence is the performance of what you asked for, together with legitimate interest.

Advertising-related processing is carried out by Google as an independent controller on the basis of your consent or its legitimate interests; where the law requires it, Google's consent management platform asks you first. We do not ourselves receive the data stored in advertising cookies.

Servers are hosted outside mainland China and several processors, including Google, are located in the United States. Transfers rely on Google's GDPR data processing terms and standard contractual clauses.

California (CCPA/CPRA)

California residents have the right to know the categories and specific pieces of personal information collected, used and disclosed; to request deletion; to request correction; and to opt out of the "sale" or "sharing" of personal information.

We do not sell personal information. Cookies used for cross-context behavioural advertising may count as "sharing" under the CCPA/CPRA; you can opt out through personalised-ads settings or your browser's cookie controls, and we will not degrade your access to the site for doing so.

Exercising any of these rights will not lead to discriminatory treatment. Write to [email protected] and we will respond within 45 days.

Children

This site is aimed at a general audience and carries teaching material about logic and reasoning. It is not directed at children under 13 and does not knowingly collect personal information from them. If you believe such information has reached us unintentionally, tell us and we will remove it.

Changes to this policy

Material changes are published on this page with an updated date at the top and noted in the footer. Continuing to use the site accepts the revised version.

Last updated: 2026-09-18.