Impotence / Erectile Dysfunction

If a male, perhaps due to a natural defect or due to castration, is without [the two testes], then he does not have... virile greenness andthis virile wind that erects the stem to its fullstrength. For that reason the stem cannot become erect to plough woman like soil, because it has lost the wind of its powers that had to strengthen it for the task of producing offspring. Similarly a plough is unable to dig up soil if it is without a ploughshare.

- Hildegard of Bingen, 12th century AD