Tertullian reports a closely related reply in an argument against pagan authorities. This is later testimony, not a surviving work by Diogenes; the popular sentence smooths the wording.
“I do not know whether there are gods, but there ought to be” — Diogenes of Sinope
Can you use it?
? We couldn’t establish where this was first published, so there’s no rights status to give. Credit it as shown above — just don’t present it as public domain, and get permission for commercial or published reuse.
Image direction — grounded in this quote’s real context; paste into your image tool
In context
Evoking the world of Diogenes of Sinope — Ancient Cynic philosopher. Theme: "I do not know whether there are gods, but there ought to be". Atmospheric and restrained, cinematic directional light, a muted period-appropriate palette, fine grain and texture. Compose with generous empty space for the quote and a small credit line. No lettering in the image itself.
Minimalist
Minimalist editorial slide for the quote "I do not know whether there are gods, but there ought to be". Clean background, a single muted accent color, generous negative space, subtle paper or linen texture, no literal illustration — let the words carry it. Reserve clear space for a serif quote and a small credit line. No lettering in the image itself.
Provenance
What the source establishes
Documented trail
Tertullian, Ad Nationes 2.2; Peter Holmes translation, Ante-Nicene Fathers, volume 3 (1885), reproduced by New Advent.
Evidence
Attribution and wording limits stated below
I do not know; only there ought to be gods.
A short excerpt from the cited source; it may differ from the popular wording above.
Read the source ↗ — Tertullian reports a closely related reply in an argument against pagan authorities. This is later testimony, not a surviving work by Diogenes; the popular sentence smooths the wording.
Holmes’s 1885 translation is pre-1931, but the exact popular English rendering has not been pinned to that edition.
Rights status is our research, not legal advice — and copyright varies by country and edition. For commercial or published use, confirm with the rightsholder. See terms.
Explore
Filed under
More provenance-checked quotes on the same theme, each with its reuse status.
Diogenes of Sinope is identified in the cited material as the ancient cynic philosopher. This page distinguishes the documented source trail from a claim of verbatim personal testimony.
For writers & researchers
Cite this
The primary source (Chicago)
Tertullian, Ad Nationes 2.2; Peter Holmes translation, Ante-Nicene Fathers, volume 3 (1885), reproduced by New Advent.
This verification page
Quotle.info. “Who really said ‘I do not know whether there are gods, but there ought to be’?” Last verified 9 Nov 2026. https://quotle.info/who-said/i-do-not-know-whether-there-are-gods-but-there-ought-to-be/