The Human Being as Subject and Object

Contra both the materialists and solipsists/Gnostics, human nature is composed of two parts–body and soul–and a human nature, or being, exists in the world as both an object and a subject.  

As Stratford Caldecott observed in his book Beauty in the Word: Rethinking the Foundations of Education:

Being, not the self, is prior to the distinction between object and subject, and the reason why Descartes and his successors were left needing to prove the existence of the external world, whereas the medievals (and other 'sane men') were not, is that he started on the purely subjective side of the divide. He reduced being to thinking. But the act of being which makes something what it is does not simply depend on me. And this in turn implies that to know a thing as given in reality involves not just the intellect but the will and the memory; not just an automatic awareness of it, or an intuition, but a yielding and giving to it, a bringing close and a standing-back-from, which transforms both subject and object in something like the way a marriage transforms the couple.

In the above passage, Caldecott was focused on the philosophers following Descartes who felt the need "to prove the existence of the external world". After Descartes' time, perhaps in reaction to such philosophical speculations divorced from the external world, scientists began to focus only on the external world, leaving aside philosophy (as classically understood). They began to focus on the purely objective side of the divide. In an analogous but different way from philosophers, the post-Cartesian scientists also imply that "to know a thing as given in reality" involves just the intellect (in a cataloguing mode), without adequate consideration of other aspects of the soul, which would involve the scientist in questions of morality and love that would challenge their materialist assumptions.