In the opinion of Bogusław Wolniewicz (1927–2017), Wittgenstein in his Tractatus presented a new metaphysics – a modern ‘metaphysics of facts’, in opposition to the traditional ‘metaphysics of substance’ (Aristotle) or to the ‘metaphysics of things’ (Tadeusz Kotarbiński’s ‘reism’). The new metaphysics describes, just like the old ones did, the structure of the world. First, it refers to the world as a whole, seeing in it an actualization of one of numerous possible worlds. It also refers to the elementary unit of world-structure, which is an ‘atomic fact’ (an independent unit, though at the same time not the simplest one, since it involves further ‘simple objects’). Those concepts of ‘world’, ‘atom’ and ‘possible beings’ make the system of Tractatus ‘metaphysics’, comparable to the Aristotle’s metaphysics of ‘form’ and ‘matter’. In Tractatus, the Aristotelian ‘matter’ turns into ‘simple objects’, while ‘form’ becomes a form of ‘fact’. In this view, the world is conceived as a set of facts and equals a particular choice made from the universe of possible situations. But one element is missing in Wittgenstein’s system, namely, the ‘efficient cause’ responsible for the choice of facts (actualization of possibilities). Leibniz believed there was a ‘sufficient reason’ why a particular choice was made among possible situations and one possible world has become real. This ‘sufficient reason’ finally turned out to be God’s rational will. In Wolniewicz’s late philosophy however, the ‘efficient cause’ is only ‘fate’ or ‘chance’ (τύχη). Fate is therefore the mysterious deus absconditus of Wittgenstein’s metaphysics.