 Bernoulli wrote the text between 1684 and 1689 , including the work of mathematicians such as Christiaan Huygens , Gerolamo Cardano , Pierre de Fermat , and Blaise Pascal . He incorporated fundamental combinatorial topics such as his theory of permutations and combinations ( the aforementioned problems from the twelvefold way ) as well as those more distantly connected to the burgeoning subject : the derivation and properties of the eponymous Bernoulli numbers , for instance . Core topics from probability , such as expected value , were also a significant portion of this important work . 
