Culpeper describes certain herbs as being under the dominion of the sun, the moon, or a planet, and others as under a planet and also one of the constellations of the Zodiac. His reasons for connecting a particular herb with a particular heavenly body are curiously inconsequent. He states, for example, that “Wormwood is an Herb of Mars, ... I prove it thus; What delights in Martial places, is a Martial Herb; but Wormwood delights in Martial places (for about Forges and Iron Works you may gather a Cart load of it) Ergo it is a Martial Herb.”
The author explains that each disease is caused by a planet. One way of curing the ailment is by the use of herbs belonging to an opposing planet—e.g. diseases produced by Jupiter are healed by the herbs of Mercury. On the other hand, the illness may be cured “by sympathy,” that is by the use of herbs belonging to the planet which is responsible for the disease.
Culpeper indulges in a strange maze of similar reasons to justify the use of Wormwood for affections of the eyes. “The Eyes are under the Luminaries; the right Eye of a Man, and the left Eye of a Woman the Sun claims Dominion over: The left Eye of a Man, and the right Eye of a Woman, are the priviledg of the Moon, Wormwood an Herb of Mars cures both[43]; what belongs to the Sun by Sympathy, because he is exalted in his House; but what belongs to the Moon by Antipathy, becaus he hath his Fal in hers.”
It is somewhat surprising to find that, in his preface, Culpeper claims that he surpasses all his predecessors in being alone guided by reason, whereas all previous writers are “as full of nonsense and contradictions as an Egg is ful of meat.”
Culpeper met with considerable opposition and criticism from his contemporaries. Shortly after his death, William Cole in his ‘Art of Simpling’ wrote scornfully of astrological botanists, “Amongst which Master Culpeper (a man now dead, and therefore I shall speak of him as modestly as I can, for were he alive I should be more plain with him) was a great Stickler; And he, forsooth, judgeth all men unfit to be Physitians, who are not Artists in Astrology, as if he and some other Figure-flingers his companions, had been the onely Physitians in England, whereas for ought I can gather, either by his Books, or learne from the report of others, he was a man very ignorant in the forme of Simples.”
It is interesting to notice that Cole, though he seems to the modern reader very credulous on the subject of the signatures of plants, was completely sceptical as to the association of astrology and botany. The main argument by which he tries to discredit it is an ingenious one. The knowledge of herbs is, he says, “a subject as antient as the Creation (as the Scriptures witnesse) yea more antient then the Sunne, or Moon, or Starres, they being created on the fourth day, whereas Plants were the third. Thus did God even at first confute the folly of those Astrologers, who goe about to maintaine that all vegitables in their growth, are enslaved to a necessary and unavoidable dependance on the influences of the Starres; Whereas Plants were, even when Planets were not.”