This is a new realist ontology based on the concept of fields of sense. Markus Gabriel presents us with an innovative answer to one of the central questions of philosophy: what is the meaning of 'being' - or, rather, 'existence' - and how does that concept relate to the totality of what there is? This ontology hinges on Gabriel's concept of fields of sense, which shows that fundamentally, he opposes the idea that mathematics or the natural sciences could ever replace a richer philosophical understanding of what there is and how we know about it. This is the first contribution to a speculative epistemology on the basis of an ontology-first method. It develops a new realist ontology as well as outlining a realist epistemology grounded in ontology.