The theme (subject) is a long one, spanning three measures, and is constructed from sequences, making the initial problem how to direct its overall trajectory.

Starting from measure 1, a descending sequence in two-beat units begins from the third beat of measure 1. The fourth beat of measure 3 is presumably a dominant (A-C#-E-G); however, considering that the D on the third beat is sustained as a suspension into the fourth beat, the dotted eighth note D on the downbeat of the fourth beat has high tension. Therefore, directing the thematic impulse towards this D is one possibility.

Typically, ascending sequences are often played with a crescendo and descending sequences with a diminuendo, though there are many exceptions. This means that this theme, starting from A in measure 1 and descending, ultimately reaches D, a perfect fifth below, so it is possible to interpret the entire theme as a diminuendo, meaning the beginning is the loudest.

On the other hand, if the direction is aimed towards the D on the downbeat of the fourth beat of measure 3, the idea is that the opening A begins pp, gradually building a crescendo, and reaching the D on the fourth beat of measure 3.

This fugue, even without considering this, contains a considerable number of sequences. What must be avoided most is for the dynamics of these sequences to become flat; it is crucial to introduce some dynamic variation. Therefore, after determining the initial direction of the theme, one should proceed in the same manner until the end; however, my personal view is to adopt the second approach, starting pp and gradually building a crescendo.