Merely inferential?

[Zans]

@zerotime

@Ceisiwr

But the Abhidhamma also argues there exist things out side of the all. Things not directly experienced, such as the water element, which can only be known by inference. That’s Rationalism rather than Empiricism.

yes, I think you are right, although also we should take it in company of remembering the arising of cohesion is a necessity instead a first conceptual fabrication. Cohesion arise because temperature, softness and pressure. Its arising will be so unavoidable like happens with the arising of time or space in dependence of their related objects.
Cohesion could be understood like a name for a summarized event. There is no touching of water but the fast experience of its related properties.

Don’t believe me each word. Water is slippery. Maybe Robert or other people can help more and correct me if I’m wrong

@Ceisiwr is correct:

The Abhidhamma holds that unlike the other three great
essentials, the water element cannot be physically sensed but must be
known inferentially from the cohesion of observed matter.
-Comprehensive Manual of Abhidhamma, Bodhi, pages 237-238

âpo is the element of cohesion. Unlike pañhavi it is
intangible.
-Narada Thera, A Manual of Abhidhamma, p 319-320