Reason for erection

An erection occurs as a result of stretching of the pudendal nerve and adjacent areas in width and length, caused by strong winds driven by thick voluptuous pneuma, along with which flows copious blood and coarse pneuma: because of this, an erection occurs in sleep, when the arteries are hot , located in the seminal organs, and the winds, pneuma and blood rush to them. Such an erection is facilitated, by the way, by everything that contains foreign moisture, which can, but not easily, turn into winds. The first digestion is not strong enough to transform this moisture into winds and destroy what has become winds or quickly dissipate them. On the contrary, the moisture remains until the third digestion and swells the penis. Carrying out copulations strengthens and thickens this organ, and when they stop, it seems to melt and become thinner. After all, work, as Hippocrates said, makes you fat, but idleness makes you thin.

The cause of passion and its movements is either generated by the imagination, or by the abundance of winds and blood from which the seed is formed; the instruments of the penis are fed by it, and the penis swells and expands. Because of this, a passion arises that moves the organ, because it is prepared for this, and, in addition, tension causes a burning sensation. In addition, when the seed finds itself in the organs of copulation, its desire to leave there intensifies, and it moves the juices in them. An erection also occurs as a result of a burning sensation caused by matter established in the glands that are located on both sides of the neck of the bladder, or by liquid, rarefied matter entering the copulatory organs from the kidneys. It also arises as a result of the movement of the seed itself, when it becomes sharp and abundant, burns and stretches the penis.