3 Metaphors for fundamental

The most fundamental of these laws is the lex continui.

Human nature is more fundamental than customs, and what would become of women if we only got our exact deserts, or had absolute justice dealt to us, either by men or other women or on the Judgment Day?

Yet the difference does not spring from anything more fundamental than environment, and therein lies the solace of the other fellow.

3 Metaphors for  fundamental