This statement is undoubtedly true, and may be taken for all it is worth. But the prima facie evidence of the works of these masters is that the writers were bent on exhausting the resources of canonic ingenuity, that their private study was all devoted to the exploration of academic counterpoint, that they worked in slavish obedience to the contrapuntal formulas which they themselves had contrived, and that their most ambitious compositions were nothing more or less than brilliant specimens of technical skill. To this estimate of their work excellent support is given by the significant criticism of Martin Luther on the writing of Josquin des Près, chief master of the second period. The great reformer said: "Josquin is a master of the notes; they have to do as he wills, other composers must do as the notes will." Furthermore the Latin formulas used in noting canons in Ockeghem's day go far toward proving that it was the mechanical ingenuity of the form which appealed to the masters of that time. They were in the habit of putting forth a canonic subject with the general indication "Ex una plures," signifying that several parts were to be evolved from one, and a special direction, such as "Ad medium referas, pausas relinque priores," darkly hinting at the manner of the working out. These riddle canons date back to Dufay's time, but they were the special delight of Ockeghem and his contemporaries. The results of such practice could only be musical mathematics, yet the masters of this period performed a lasting service to art; for they laid down rules for this kind of composition and in their own works indicated the path by which artistic results might be reached by their successors. The highest praise that can be awarded to their works is that they are profound in their scholarship, not without evidences of taste in the selection of the formulas to be employed, and certainly imbued with a good deal of the dignity which would inevitably result from a skilful contrapuntal treatment of the church chant. Ambros finds evidences of design in one of Ockeghem's motets, from which he quotes, but the design is certainly not of the kind which would call for praise if discovered in contemporaneous music. Naumann, who is quite carried away by the improvement of the first Netherlands compositions over those of the French contrapuntists, is warm in his praise of these early canonists. He says: