> TARTAGLIA says that Cardano had sworn not to publish the result.
> This is in his Quesiti. But Lodovico Ferrari, apostrophied by
> Tartaglia as "il suo creato", says in his second Cartello di sfida
> that he was also present in the house of Cardano in Milan when
> Cardano and Tartaglia were talking to each other and that Tartaglia
> were telling lies. So it is not clear whether Cardano ever swore
> an oath. Ferrari also mentions in this cartello that he and Cardano
> went to Bologna where they saw a note book of Ferro's with the
> solution of the equation of the first type. And, after all, the
> result is one that must be made public, it has to be known by all
> mathematicians. Cardano has no right to withhold it. Moreover,
> Cardano had the solution for all types of cubic equations, no
> exceptions. .....
> Did Cardano swear an oath? We shall never know, I think.
Quite clear, I believe.
Just one more question: Anyhow, Ferrari was a disciple of Cardano, and
there are reports that he (Ludovico) was, since fourteen years old, a
servant in Cardano's house. Do you think that his testimony may have
been biased?
Arturo Mena