Analysis of The Tree Of Knowledge

I PLUCKED the blossoms of delight
In many a wood and many a field,
I made a garland fair and bright
As any gardens yield.

But when I sought the living tree
To make new earth and Heaven new,
I found--alas for you and me--
Its roots were set in you.

Oh, dear my garden, where the fruit
Of lovely knowledge sweetly springs,
How jealously you guard the root
Of all enlightening things!