at one

She felt perfectly at one with nature during her retreat to the lake.

Vidal's old antagonist Norman Mailer was largely at one with him on this, jauntily alleging that endless war was the only way to vindicate the drooping virility of the traditional white American male.

And the next daye he shewed himsilfe unto them as they strove, and wolde have sett them at one agayne saynge: Syrs ye are brethren why hurte ye won another?