The aim of this paper is to present the copy principle from execution of the principle of separability for the purpose of elucidating the discussions conducted by Hume in understanding the composition of space and its implications for the sciences that operate with spatial constructions. The particular epistemic gain here is to do this within a model of empiricism. Given that there are several irregularities in the manner of analyzing a complex and extracting simple elements from it, as will be (...) demonstrated here, we seek to show that separating a complex considering its simple qualities and decomposing a complex to determine its simple quantities is completely different. Thus, we seek to show how Hume needed to recreate his own cognitive model, strongly based on noting our perceptions, to be able to use it to conceive the composition of space and the operations of geometry that must make reference to it. (shrink)