Sapiens nihil affirmat quod non probat

This paper responds to Ernesto Screpanti's critique of Guglielmo Carchedi's approach to Marx's transformation procedure. It argues that there is no logical inconsistency in that procedure once one introduces time, rather than denying it as Marx's critics do. Further, it examines Screpanti's critique and argues that, while Marx's algebra is correct, Screpanti's own 'refutation' of Marx is invalid because it balances neither in physical nor in algebraic terms. It finally examines some old critiques which, while presented by Screpanti as novel, are well-known acquaintances which have already been shown to be invalid. Two conclusions are reached. First, Screpanti concedes that the circularity critique does not hold when time is introduced in the analysis and, second, Screpanti's critique is an attempt to vindicate a method of inquiry (simultaneism) which is unsuited to understanding what really matters, a temporal situation, i.e. reality.