 Wittgenstein’s later work on philosophy of mathematics, such as the Remarks on the Foundations of Mathematics 1956/1978), for a long time attracted even less approval than the Tractarian account, though recently philosophers such as Juliet Floyd and Hilary Putnam have come to its defence as an interesting and informed account of mathematics (Floyd/Putnam, 2000). Its themes include the rejection of the actual infinite (indeed the tendency in his writings is strongly finitist); the denial that undecidable sentences are meaningful; a rejection of Cantor’s powerset proof; the idea that proof discovery changes the very meaning of the terms involved; and other very radical ideas. Among them we find a continued adherence to formalist motifs: