Hildegard more especially emphasizes the influence of the moon, in which respect she resembles many an astrologer. In the _Causae et curae_[439] she states that some days of the moon are good, others bad; some, useful and others, useless; some, strong and others, weak. “And since the moon has this changeability in itself, therefore the moisture in man has its vicissitudes and mutability in pain, in labor, in wisdom, and in prosperity.” Similarly in the _Liber divinorum operum_[440] it is noted that human blood and brain are augmented when the moon is full and diminish as it wanes, and that these changes affect human health variously. Sometimes one incurs epilepsy when the moon is in eclipse.[441] The moon is the mother of all seasons. Hildegard marvels in the _Causae et curae_[442] that while men have sense enough not to sow crops in mid-summer or the coldest part of winter, they persist in begetting offspring at any time according to their pleasure without regard either to the proper period of their own lives or to the time of the moon. The natural consequence of their heedlessness is the birth of defective children. Hildegard then adds[443] by way of qualification that the time of the moon does not dominate the nature of man as if it were his god, or as if man received any power of nature from it, or as if it conferred any part of human nature. The moon simply affects the air, and the air affects man’s blood and the humors of his body. [Sidenote: Relations of the four humors to human character and fate.]