Air is the singularity of Nature

"The single quotation preserved from his [Anaximenes] work asserts that, 'just as our soul, being air, holds us together, so do breath and air encompass the whole world.' This contains perhaps a hint why Nature was identified with air. The belief was widespread that the soul - the life principle of living things - was a vaporous substance, maintained during life in the body by respiration and finally exhaled at death only with the last breath. That Nature should be conceived as the self-evolving vital principle of the universe, as we have seen that it was by Milesian Philosophy, meant that the world was being interpreted after the analogy with living beings, and this way in some measure makes more intelligible Anaximenes' doctrine that Nature is air. Condensation and rarefaction are the respiration of a living cosmos; Nature is its breath of life." - Martin, Clark, Ckarke, Ruddick, A History of Philosophy, Pg. 18