Yes, I like that too! That principle eventually becomes the Yoneda Lemma in category theory. I really like Tae-Danae Bradley's highly readable blog posts explaining this:

* [The Yoneda perspective](

* [The Yoneda embedding](

* [The Yoneda lemma](

The "Yoneda perspective", in her words, is that

> An object is completely determined by its relationships to other objects.