MahāvaggavaggaSabbamatthītikathā

Abhidhammapiṭaka · Kathāvatthu · Vol. 37 · Section 380

[380] [Sakavādin:] Does the future (anāgata) exist? [Paravādin:] Yes. [Sakavādin:] Is that which exists future? [Paravādin:] That which exists may be future, or may not be future. [Sakavādin:] Acknowledge the refutation (niggaha): If the future exists, and that which exists may be future or may not be future, then the future is not future, and what is not future is future. What you assert there — namely, that it can indeed be said, "The future exists; that which exists may be future or may not be future; thereby the future is not future, and what is not future is future" — is wrong. But if it should not be said that the future is not future and that what is not future is future, then truly it should not be said, "The future exists; that which exists may be future or may not be future." What you assert there — namely, that it can indeed be said, "The future exists; that which exists may be future or may not be future; thereby the future is not future, and what is not future is future" — is wrong.

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.