Through you color, form, location, sublimity, ideality, Through you every proof, comparison, and all the suggestions and determinations of ourselves. (lines 139-140)
At the end of the poem, he says that our identity is like a mosaic of things grand and small. We are "determined' by our environments and the things we encounter in the world. We're not just a bunch of pre-made souls that plow through the world without begin changed by it. A simple point, maybe, but a profound one.