   We noted that Leśniewski, persuaded by his argument against Twardowski’s general objects, was a nominalist. It was no doubt part of his antipathy towards set theory. His friend Kotarbiński formulated a very extreme nominalism, called variously reism, pansomatism, and concretism, according to which the only things that exist are material bodies. Leśniewski would not go this far, because he did not see how after-images and dreamt things, which he thought existed, could be material bodies. But in elaborating his logic he emphatically rejects anything which is not concrete, individual, located in space and time. This goes for the logical systems themselves. His view, which would nowadays be called inscriptionalism, is that logical systems are actual collections of concrete marks, whether printed on paper in books and journals, or in handwritten notes, or more ephemerally as spoken words, chalk marks on blackboards, or (nowadays) patterns on computer screens. Leaving aside the non-trivial metaphysical question of what can in principle count as a logical inscription, we must consider what effect this stance had on his attitude to logic and logic systems.