St。ThomasAquinasinsistedthattheforcesofthebodyareindependentofitsphysicalorganization，andthatthereforetheseforcesaretobestudiedbythescholasticphilosophyandthetheologicalmethod，insteadofbyresearchesintothestructureofthebody；asaresultofthis，mingledwithsurvivalsofvariouspagansuperstitions，wehaveinanatomyandphysiologysuchdoctrinesastheincreaseanddecreaseofthebrainwiththephasesofthemoon，theebbandflowofhumanvitalitywiththetidesoftheocean，theuseofthelungstofantheheart，thefunctionoftheliverastheseatoflove，andthatofthespleenasthecentreofwit。
Closelyconnectedwiththesemethodsofthoughtwasthedoctrineofsignatures。ItwasreasonedthattheAlmightymusthavesethissignuponthevariousmeansofcuringdiseasewhichhehasprovided：henceitwasheldthatbloodroot，onaccountofitsredjuice，isgoodfortheblood；liverwort，havingaleafliketheliver，curesdiseasesoftheliver；eyebright，beingmarkedwithaspotlikeaneye，curesdiseasesoftheeyes；celandine，havingayellowjuice，curesjaundice；bugloss，resemblingasnake’shead，curessnakebite；redflannel，lookinglikeblood，curesblood-taints，andthereforerheumatism；bear’sgrease，beingtakenfromananimalthicklycoveredwithhair，isrecommendedtopersonsfearingbaldness。[308]
[308]Forasummaryofthesuperstitionswhicharoseunderthetheologicaldoctrineofsignatures，seeDr。Eccles’sadmirablelittletractontheEvolutionofMedicalScience，p。140；seealsoScoffern，ScienceandFolkLore，p。76。
Stillanothermethodevolvedbythistheologicalpseudosciencewasthatofdisgustingthedemonwiththebodywhichhetormented——hencethepatientwasmadetoswalloworapplytohimselfvariousunspeakableordures，withsuchmedicinesastheliversoftoads，thebloodoffrogsandrats，fibresofthehangman’srope，andointmentmadefromthebodyofgibbetedcriminals。Manyoftheseweresurvivalsofheathensuperstitions，buttheologicreasoningwroughtintothemanorthodoxsignificance。AsanexampleofthismixtureofheathenwithChristianmagic，wemaycitethefollowingfromamedievalmedicalbookasasalveagainst“nocturnalgoblinvisitors“：
“Takehopplant，wormwood，bishopwort，lupine，ash-throat，henbane，harewort，viper’sbugloss，heathberryplant，cropleek，garlic，grainsofhedgerife，githrife，andfennel。Putthesewortsintoavessel，setthemunderthealtar，singoverthemninemasses，boiltheminbutterandsheep’sgrease，addmuchholysalt，strainthroughacloth，throwthewortsintorunningwater。Ifanyilltemptingoccurtoaman，oranelforgoblinnightvisitorscome，smearhisbodywiththissalve，andputitonhiseyes，andcensehimwithincense，andsignhimfrequentlywiththesignofthecross。Hisconditionwillsoonbebetter。”[309]