Bogusław Wolniewicz created an original formal system based on his considerations on the ontology and semantics embedded in Wittgenstein’s Tractatus. His system – called by Wolniewicz ‘ontology of situations’ – can be complemented by a philosophical interpretation. In this article I identify the implicit and intuitive underpinnings of the system, its formal content and its philosophical implications. I also indicate a few applications of the system to axiology and logical hermeneutics.