The Principles
Fifth Lesson

To achieve the boldness and precision of strokes I've just mentioned, we propose the following example.

Example

A, indicates two straight lines; B, two transverse lines. C, two oblique lines; D, the horizon; E, the point of view; F, the ground line; and G, the line of distance.

Initially, we only see lines familiar to our student, and these must be executed well. Instead of calling them two straight, transverse, or oblique lines, we teach him to call them parallels here. Every artistic stroke must have its particular name, and this is most appropriate, as will become clear later. We aim to give our student an exact idea of things as we discuss them, so he doesn't act blindly and confuse shadow for substance, as those in darkness do. For this reason, we do not overwhelm him here with numerous examples or stories, which would confuse rather than help him, and this method might suit a historian better than a teacher. While we occasionally provide an example or comparison, we do so briefly and in a way that aligns as closely as possible with the subject. Further on, when we advance, we will present more complex figures as needed.

Moreover, remember that the transverse line dividing the board is called the Horizon, and the little eye in the middle is called the point of view. The two lines emanating from it, and all others drawn from there, form visual rays. The line running below is the Ground Line. The two lines drawn from both sides of the Horizon are called...

Translation Notes:

Parallels: Lines that constantly maintain the same distance apart and never meet, crucial for perspective drawing.

Visual Rays: Imaginary lines extending from the viewer's eye to the object, essential for understanding perspective.