Absolutes are perhaps better understood as what Stirner called "fixed ideas". Proudhon opposed the absolute to progress, understood as movement and change.

[Absolutism] is the study, in nature, society, religion, politics, morals, etc., of the eternal, the immutable, the perfect, the definitive, the unconvertible, the undivided; it is, to use a phrase made famous in our parliamentary debates, in all and everywhere, the status quo.

Undivided is perhaps a key characteristic. The absolute is an empty, indivisible unity. Only in division, in series, in 'mutual penetration' with antagonistic terms, does a term gain meaning. Which implies movement, progression.

All that reason knows and affirms is that the being, as well as the idea, is a group. [...]

Of or by anyone.