Francis Herbert Bradley (1846-1924) Appearance and Reality. A Metaphysical Essay (1893) 6. app. 1916
Book II. Reality.
Chapter XXVII. Ultimate Doubts.
...A thing is real when, and in so far as, its opposite is impossible. But in the end its opposite is impossible because, and in so far as, the thing is real. And, according to the amount of reality which anything possesses, to that extent its opposite is inconceivable. The more, in other words, that anything exhausts the field of possibility, the less possible becomes that which would essentially alter it. Now, in the case of such truth as we have called absolute, the field of possibility is exhausted. Reality is there, and the opposite of Reality is not privation but absolute nothingness. There can be no outside, because already what is inside is everything. But the case is altered when we come to subordinate truths.
Chapter XXVII. Ultimate Doubts.
...A thing is real when, and in so far as, its opposite is impossible. But in the end its opposite is impossible because, and in so far as, the thing is real. And, according to the amount of reality which anything possesses, to that extent its opposite is inconceivable. The more, in other words, that anything exhausts the field of possibility, the less possible becomes that which would essentially alter it. Now, in the case of such truth as we have called absolute, the field of possibility is exhausted. Reality is there, and the opposite of Reality is not privation but absolute nothingness. There can be no outside, because already what is inside is everything. But the case is altered when we come to subordinate truths.