The only letters in these lines which mean nothing are l, n, r, t and small b and d; all the others have a signification. For example, the _vowels_ of the italicized words signify the various valid moods, as e. g., the first line indicates the moods AAA, EAE, AII, EIO. The Latin words, printed in ordinary type, are intended to make evident that the moods indicated by the artificial italicized words of the first line, belong to the _first_ figure; that the moods of the next four words, belong to the _second_ figure; while the _third_ figure includes the next six, and the _fourth_ figure the last five. It is now seen that Festino, for example, stands for that mood of the second figure which has an E for its major premise, an I for its minor premise, and an O for its conclusion. The first figure was called by Aristotle the _perfect figure_, whereas the second and third were the _imperfect figures_. The fourth figure was given no place in the works of Aristotle; its discovery is credited to Galen, a celebrated teacher of medicine of the second century. According to Aristotle, the first figure is the most serviceable and the most convincing and, therefore, as a final test of their validity, the moods of the other figures should be changed to the _first_. This process in logic is termed _Reduction_. In this reduction of the imperfect figures to the perfect, the _capital letters_ of the artificial words, together with s, p, m, and k, have a definite meaning. The capital letters indicate that certain moods of the imperfect figures can be reduced to the corresponding moods of the first figure; e. g., Festino (eio) of the second figure, Felapton (eao) of the third figure, and Fesapo (eao) of the fourth figure may all be reduced to Ferio (eio) of the first figure. This is known because _F_ is the initial letter of each word. _s_ signifies that the proposition denoted by the preceding vowel is to be converted simply. To illustrate: _s_ E in Fesapo means that the major premise E of the mood A of the fourth O figure must be converted _simply_ in order to change the mood to Ferio of the first figure. _p_ indicates that the proposition represented by the vowel which precedes p must be converted by _limitation_ (per accidens). _m_ (mutare) makes evident that the premises are to be interchanged, the major of the old becoming the minor of the new, and the minor of the old becoming the major of the new. _k_ denotes that the mood, such as Baroko, must be reduced by a special process known as _indirect reduction_. These directions may now be followed as illustrative of the process of reduction.