I had been told how early human beings first started making marks that represented this or that – the beginnings of language.

“And this helped them to think about those things?”

For the first time, thought can be detached from objects.  Plans can become abstract, long-term, not just emergent possibilities inherent in situations, as they are for animals.  The response to other creatures can be evaluative, normative.  It becomes possible to notice that a particular action falls short of the best or right action, that a particular human being falls short of the ideal human being.