Comment by Geldner:
THE VERDICT (Lines 48-54)
It was probably rare that a court in Mainz had to reach a judgement in such a complicated case. Insofar as we can form a valid opinion today, without access to Fust's reply and Gutenberg's rejoinder, it seems the court performed this task to the best of its knowledge and in good faith. In a wise display of restraint, it only passed judgement on the first article of Fust's claim, evidently taking into consideration Gutenberg's response to Fust's complaint, which was doubtless further explained and expanded on by Gutenberg in his rejoinder (now lost). In his reply to Gutenberg's answer, Fust presumably had to admit that there was a fundamental difference between the loan (the first 800 guilders, if we stick to the sum originally named by Fust), intended for the manufacture of the printing equipment, which was to be pledged to Fust as collateral, and the capital contribution (the second 800 guilders paid by Fust in installments) intended for the work on the books (the work to their common good). Concerning the second 800 guilders, the court began by judging:
once Gutenberg had fulfilled his offer by accounting for all expenditure and revenue resulting from the joint undertaking, any positive balance should be added to the 800 guilders (the court clearly assumed that such income had already been generated by sales of printed matter). The court was obviously of the opinion that whatever Gutenberg acquired with these 800 guilders plus any other revenue (i.e. the work of the books), belonged to the two partners in equal parts, as was customary in such partnerships if nothing was agreed to the contrary.
If these accounts showed that Fust had given Gutenberg money above and beyond 800 guilders which had not been used to their common advantage, then Gutenberg was to pay this sum back too. And if Johannes Fust proved by oath or witnesses that the aforementioned sum was not taken from his own capital but borrowed against interest at his own expense, then Gutenberg was also to pay this interest.
The aforementioned sum not used to their common good refers to the 800+x guilders which Gutenberg considered as an interest-free loan and which were intended for the manufacture of the pledged printing equipment. The court obviously considered the various sums of money given by Fust to Gutenberg as a single item (as did Fust). The money not used for their joint project was to be paid back with interest, insofar as Fust could prove that he had paid interest on it himself. This decision seems justified. But in practice, how was a decision to be reached on what Gutenberg had needed for his equipment and what had been spent on work to their common benefit, if, for example, Gutenberg used his own new type printing equipment (sein geczuge) for their joint book project (werck der bucher)? It was not easy to determine the degree to which the newly created moveable types belonged to the joint project, as Fust had continued to make payments with no clear distinction between loan and capital contribution. The judgement was final and not interlocutory as ZEDLER thought but it was only a part judgement, subject to certain restrictions.