>>13144377Fun fact time! OP is utilising what we know as 'the flow story'! It is basically what was the first thing to go in the first flow.
Vagus Story Differentiation
What OP is asking is what was the first thing to exist to measure, which would imply that the measurer was the second inarguable thing to exist as the measurer is not the arguer it is simply taking a measurement of abstraction in order to either detect or determine the allowances of the thing it is measuring to exist stably.
From the measurer's perspective the first thing to exist is potential because it would need to probe/inspect a space before it could hope to gain anything.
Afterwards the rest follows basic predicate laws as everything that the measurer consumes to continue its existence would require to exist prior to its ability to measure.