The Nine Subjects
This part deals with the nine subjects signified in the alphabet; these subjects comprise everything that exists and there is nothing outside of these. The first subject is God, signified by B. The second subject is about angels, signified by C. The third subject is heaven, signified by D. The fourth subject is man, signified by E. The fifth is the imagination, signified by F. The sixth subject is the sensitive power, signified by G. The seventh subject is the vegetative power, signified by H. The eighth subject is the elementative, signified by I. the ninth subject is the instrumentative, signified by K.
Because in Ars Magna each subject is combined with the sequence of principles and rules, we do not reproduce this discourse here, because we want this Art to be an abridged version of Ars Magna, and because this combination is implicit in Ars Brevis. For these reasons, we leave it up to the diligent intellect to work this out. It is enough to follow the example given in the third figure, where all the principles are applied to goodness; and also Part Four where "intellect" is applied to all the rules of this Art.
Here is the first condition: each subject must have its definition, which distinguishes it from all other subjects. And if a question is put about a subject, it must be answered either negatively or positively so that the definitions of the principles agree with the definition of the subject; and likewise with the rules, so that the principles and the rules are not violated in any way.