We know in effect that the notion of limit has lost its phoronomic character and involves only static considerations; that variability has ceased to represent a progression through all the values of an interval and come to mean only the disjunctive assumption of one value within that interval; that the derivative and the integral have become ordinal rather than quantitative concepts; and finally that the differential designates only a magnitude left undetermined so that it can be made smaller than a given number as required.