Understanding 'rather do we'

Solution 1:

The text is from a translation of Schopenhauer. There are commas after "is" and "will", and you have omitted some words. From the translation at bartleby.com:

Rather do we freely acknowledge that what remains after the entire abolition of will is, for all those who are still full of will, certainly nothing; but, conversely, to those in whom the will has turned and has denied itself, this our world, which is so real, with all its suns and Milky Ways — is nothing.

The phrase "for all those who are still full of will" is parenthetical.

I'd paraphrase "Rather do we" as "Rather, we" or "On the contrary, we".