Two kinds of individuals are distinguished: abstract and concrete. Whereas abstract individuals belong to our conceptual sphere, concrete individuals (i.e. particulars) individuate the world of matter. A subject inquiring the external world projects abstract individuals onto the concrete ones (i.e. pieces of matter). Our theory offers a solution to various ontological and epistemological puzzles concerned with individuals, e.g., the Ship of Theseus, Polish Logician, problems with reidentification, or proper names.