The paper argues that Sergej Bulgakov's sophiology was an attempt, via antinomism or the philosophy of antinomies, to overcome the rationalism, monism, and determinism (in a word, "pantheism") of Vladimir Solov'ëv's philosophy of the Absolute understood as an abstract Trinitarianism. After detailing Solov'ëv's thought on the Trinity and Bulgakov's criticisms of it, the study then describes Bulgakov's antinomism and its application to the doctrine of God. However, it is contended that Bulgakov's antinomism ultimately falls into the same problems with pantheism found in Solov'ëv and so the last part of the paper tentatively proposes resources in his work, stated in the form of a suggested "fourth (Bulgakovian) antinomy" between ousia (divine Being as such) and Sophia (the revelation in God and the world of the divine Being), that might help to avoid a collapse of God and the world by making the divine Being proper utterly transcendent and unknowable.