One important source of error with regard to cause and effect lies in the general and profound supposition that the cause must have a certain similarity to the effect. So Ovid, according to J. S. Mill, has Medea brew a broth of long-lived animals; and popular superstitions are full of such doctrine. The lung of a long-winded fox is used as a cure for asthma, the yarrow is used to cure jaundice, agaricos is used for blisters, aristolochia (the fruit of which has the form of a uterus) is used for the pains of child-birth, and nettle-tea for nettle-rash. This series may be voluntarily increased when related to the holy patron saints of the Catholic Church, who are chosen as protectors against some especial condition or some specific difficulty because they at one time had some connection with that particular matter. So the holy Odilia is the patron saint for diseases of the eye, not because she knew how to cure the eyes, but because her eyes were put out with needles. The thief Dismas is the patron of the dying because we know nothing about him save that he died with Christ. St. Barbara, who is pictured together with a tower in which she was imprisoned, and which was supposed to be a powder house, has become the patron saint of artillery. In the same manner St. Nicholas is, according to Simrock, the patron of sailors because his name resembles Nichus, Nicor, Nicker, which is the name of the unforgotten old German sea-deity. Against such combinations, external and unjustified, not even the most educated and skilful is safe. Nobody will doubt that he is required to make considerable effort in his causal interpretation because of the sub-conscious influence of such similarities. The matter would not be so dangerous, all in all, because such mistakes may be easily corrected and the attention of people may be called to the inadequacy of such causation--but the reason for this kind of correlations is rarely discovered. Either people do not want to tell it because they instinctively perceive that their causal interpretation cannot be justified, or they cannot even express it because the causal relation had been assumed only subconsciously, and they are hence unaware of the reasons for it and all the more convinced that they are right. So for example, an intelligent man told me that he suspected another of a murder because the latter’s mother died a violent death. The witness stuck to his statement: “the man who had once had something to do with killing must have had something to do with this killing.” In a similar manner, a whole village accused a man of arson because he was born on the night on which a neighboring village burned down. Here, however, there was no additional argument in the belief that his mother had absorbed the influence of the fire inasmuch as the latter was told that there had been a fire only after the child was born. “He once had something to do with fire,” was the basis of the judgment, also in this case.