Tadeusz Kotarbiski is widely recognized as a major philosopher of theLvov–Warsaw school. His reism, which is a contribution to semantics andontology, is still discussed and debated, and his most original creation, praxiology,has grown into an entire research field. However, Kotarbiski's philosophy ofscience has not received much attention by later commentators. This paper attemptsto correct this situation by considering the hypothesis that Kotarbiski succeededalready in 1929 in formulating a position that can be regarded as an early version ofscientific realism. Unlike most (...) other ``scientific philosophers'' before the mid-thirties,he was able to combine ontological realism (by defending a form of physicalism andnominalism) and semantical realism (by defending the classical correspondence theoryof truth). He was also a critical epistemological realist. Further, in spite of theinstrumentalist flavour of his reductionist programme in eliminating terms apparentlyreferring to abstract entities, Kotarbiski accepted theories as statements with truth values and theoretical entities as long as they can be understood as physical bodies. (shrink)