a history of science-2- 第1部分

A　History　of　Science；　Volume　2
by　Henry　Smith　Williams；　M。D。；　LL。D。
ASSISTED　BY
EDWARD　H。　WILLIAMS；　M。D。
IN　FIVE　VOLUMES
VOLUME　II。


CONTENTS
BOOK　II
CHAPTER　I。　SCIENCE　IN　THE　DARK　AGE
CHAPTER　II。　MEDIAEVAL　SCIENCE　AMONG　THE　ARABIANS
CHAPTER　III。　MEDIAEVAL　SCIENCE　IN　THE　WEST
CHAPTER　IV。　THE　NEW　COSMOLOGYCOPERNICUS　TO　KEPLER　AND　GALILEO
CHAPTER　V。　GALILEO　AND　THE　NEW　PHYSICS
CHAPTER　VI。　TWO　PSEUDO…SCIENCESALCHEMY　AND　ASTROLOGY
CHAPTER　VII。　FROM　PARACELSUS　TO　HARVEY
CHAPTER　VIII。　MEDICINE　IN　THE　SIXTEENTH　AND　SEVENTEENTH　CENTURIES
CHAPTER　IX。　PHILOSOPHER…SCIENTISTS　AND　NEW　INSTITUTIONS　OF
LEARNING
CHAPTER　X。　THE　SUCCESSORS　OF　GALILEO　IN　PHYSICAL　SCIENCE
CHAPTER　XI。　NEWTON　AND　THE　COMPOSITION　OF　LIGHT
CHAPTER　XII。　NEWTON　AND　THE　LAW　OF　GRAVITATION
CHAPTER　XIII。　INSTRUMENTS　OF　PRECISION　IN　THE　AGE　OF　NEWTON
CHAPTER　XIV。　PROGRESS　IN　ELECTRICITY　FROM　GILBERT　AND　VON
GUERICKE　TO　FRANKLIN
CHAPTER　XV。　NATURAL　HISTORY　TO　THE　TIME　OF　LINNAEUS
APPENDIX

A　HISTORY　OF　SCIENCE　BOOK　II　THE　BEGINNINGS　OF　MODERN　SCIENCE　The　studies　of　the　present　book　cover　the　progress　of　science　from　the　close　of　the　Roman　period　in　the　fifth　century　A。D。　to　about　the　middle　of　the　eighteenth　century。　In　tracing　the　course　of　events　through　so　long　a　period；　a　difficulty　becomes　prominent　which　everywhere　besets　the　historian　in　less　degreea　difficulty　due　to　the　conflict　between　the　strictly　chronological　and　the　topical　method　of　treatment。　We　must　hold　as　closely　as　possible　to　the　actual　sequence　of　events；　since；　as　already　pointed　out；　one　discovery　leads　on　to　another。　But；　on　the　other　hand；　progressive　steps　are　taken　contemporaneously　in　the　various　fields　of　science；　and　if　we　were　to　attempt　to　introduce　these　in　strict　chronological　order　we　should　lose　all　sense　of　topical　continuity。　Our　method　has　been　to　adopt　a　compromise；　following　the　course　of　a　single　science　in　each　great　epoch　to　a　convenient　stopping…point；　and　then　turning　back　to　bring　forward　the　story　of　another　science。　Thus；　for　example；　we　tell　the　story　of　Copernicus　and　Galileo；　bringing　the　record　of　cosmical　and　mechanical　progress　down　to　about　the　middle　of　the　seventeenth　century；　before　turning　back　to　take　up　the　physiological　progress　of　the　fifteenth　and　sixteenth　centuries。　Once　the　latter　stream　is　entered；　however；　we　follow　it　without　interruption　to　the　time　of　Harvey　and　his　contemporaries　in　the　middle　of　the　seventeenth　century；　where　we　leave　it　to　return　to　the　field　of　mechanics　as　exploited　by　the　successors　of　Galileo；　who　were　also　the　predecessors　and　contemporaries　of　Newton。　In　general；　it　will　aid　the　reader　to　recall　that；　so　far　as　possible；　we　hold　always　to　the　same　sequences　of　topical　treatment　of　contemporary　events；　as　a　rule　we　treat　first　the　cosmical；　then　the　physical；　then　the　biological　sciences。　The　same　order　of　treatment　will　be　held　to　in　succeeding　volumes。　Several　of　the　very　greatest　of　scientific　generalizations　are　developed　in　the　period　covered　by　the　present　book：　for　example；　the　Copernican　theory　of　the　solar　system；　the　true　doctrine　of　planetary　motions；　the　laws　of　motion；　the　theory　of　the　circulation　of　the　blood；　and　the　Newtonian　theory　of　gravitation。　The　labors　of　the　investigators　of　the　early　decades　of　the　eighteenth　century；　terminating　with　Franklin's　discovery　of　the　nature　of　lightning　and　with　the　Linnaean　classification　of　plants　and　animals；　bring　us　to　the　close　of　our　second　great　epoch；　or；　to　put　it　otherwise；　to　the　threshold　of　the　modern　period；

I。　SCIENCE　IN　THE　DARK　AGE　An　obvious　distinction　between　the　classical　and　mediaeval　epochs　may　be　found　in　the　fact　that　the　former　produced；　whereas　the　latter　failed　to　produce；　a　few　great　thinkers　in　each　generation　who　were　imbued　with　that　scepticism　which　is　the　foundation　of　the　investigating　spirit；　who　thought　for　themselves　and　supplied　more　or　less　rational　explanations　of　observed　phenomena。　Could　we　eliminate　the　work　of　some　score　or　so　of　classical　observers　and　thinkers；　the　classical　epoch　would　seem　as　much　a　dark　age　as　does　the　epoch　that　succeeded　it。　But　immediately　we　are　met　with　the　question：　Why　do　no　great　original　investigators　appear　during　all　these　later　centuries？　We　have　already　offered　a　part　explanation　in　the　fact　that　the　borders　of　civilization；　where　racial　mingling　naturally　took　place；　were　peopled　with　semi…barbarians。　But　we　must　not　forget　that　in　the　centres　of　civilization　all　along　there　were　many　men　of　powerful　intellect。　Indeed；　it　would　violate　the　principle　of　historical　continuity　to　suppose　that　there　was　any　sudden　change　in　the　level　of　mentality　of　the　Roman　world　at　the　close　of　the　classical　period。　We　must　assume；　then；　that　the　direction　in　which　the　great　minds　turned　was　for　some　reason　changed。　Newton　is　said　to　have　alleged　that　he　made　his　discoveries　by　〃intending〃　his　mind　in　a　certain　direction　continuously。　It　is　probable　that　the　same　explanation　may　be　given　of　almost　every　great　scientific　discovery。　Anaxagoras　could　not　have　thought　out　the　theory　of　the　moon's　phases；　Aristarchus　could　not　have　found　out　the　true　mechanism　of　the　solar　system；　Eratosthenes　could　not　have　developed　his　plan　for　measuring　the　earth；　had　not　each　of　these　investigators　〃intended〃　his　mind　persistently　towards　the　problems　in　question。　Nor　can　we　doubt　that　men　lived　in　every　generation　of　the　dark　age　who　were　capable　of　creative　thought　in　the　field　of　science；　bad　they　chosen　similarly　to　〃intend〃　their　minds　in　the　right　direction。　The　difficulty　was　that　they　did　not　so　choose。　Their　minds　had　a　quite　different　bent。　They　were　under　the　spell　of　different　ideals；　all　their　mental　efforts　were　directed　into　different　channels。　What　these　different　channels　were　cannot　be　in　doubtthey　were　the　channels　of　oriental　ecclesiasticism。　One　all…significant　fact　speaks　volumes　here。　It　is　the　fact　that；　as　Professor　Robinson＇1＇　points　out；　from　the　time　of　Boethius　（died　524　or　525　A。D。）　to　that　of　Dante　（1265…1321　A。D。）　there　was　not　a　single　writer　of　renown　in　western　Europe　who　was　not　a　professional　churchman。　All　the　learning　of　the　time；　then；　centred　in　the　priesthood。　We　know　that　the　same　condition　of　things　pertained　in　Egypt；　when　science　became　static　there。　But；　contrariwise；　we　have　seen　that　in　Greece　and　early　Rome　the　scientific　workers　were　largely　physicians　or　professional　teachers；　there　was　scarcely　a　professional　theologian　among　them。　Similarly；　as　we　shall　see　in　the　Arabic　world；　where　alone　there　was　progress　in　the　mediaeval　epoch；　the　learned　men　were；　for　the　most　part；　physicians。　Now　the　meaning　of　this　must　be　self…evident。　The　physician　naturally　〃intends〃　his　mind　towards　the　practicalities。　His　professional　studies　tend　to　make　him　an　investigator　of　the　operations　of　nature。　He　is　usually　a　sceptic；　with　a　spontaneous　interest　in　practical　science。　But　the　theologian　〃intends〃　his　mind　away　from　practicalities　and　towards　mysticism。　He　is　a　professional　believer　in　the　supernatural；　he　discounts　the　value　of　merely　〃natural〃　phenomena。　His　whole　attitude　of　mind　is　unscientific；　the　fundamental　tenets　of　his　faith　are　based　on　alleged　occurrences　which　inductive　science　cannot　admitnamely；　miracles。　And　so　the　minds　〃intended〃　towards　the　supernatural　achieved　only　the　hazy　mysticism　of　mediaeval　thought。　Instead　of　investigating　natural　laws；　they　paid　heed　（as；　for　example；　Thomas　Aquinas　does　in　his　Summa　Theologia）　to　the　〃acts　of　angels；〃　the　〃speaking　of　angels；〃　the　〃subordination　of　angels；〃　the　〃deeds　of　guardian　angels；〃　and　the　like。　They　disputed　such　important　questions　as；　How　many　angels　can　stand　upon　the　point　of　a　needle？　They　argued　pro　and　con　as　to　whether　Christ　were　coeval　with　God；　or　whether　he　had　been　merely　created　〃in　the　beginning；〃　perhaps　ages　before　the　creation　of　the　world。　How　could　it　be　expected　that　science　should　flourish　when　the　greatest　minds　of　the　age　could　concern　themselves　with　problems　such　as　these？　Despite　our　preconceptions　or　prejudices；　there　can　be　but　one　answer　to　that　question。　Oriental　superstition　cast　its　blight　upon　the　fair　field　of　science；　whatever　compensation　it　may　or　may　not　have　brought　in　other　fields。　But　we　must　be　on　our　guard　lest　we　overestimate　or　incorrectly　estimate　this　influence。　Posterity；　in　glancing　backward；　is　always　prone　to　stamp　any　given　age　of　the　past　with　one　idea；　and　to　desire　to　characterize　it　with　a　single　phrase；　whereas　in　reality　all　ages　are　diversified；　and　any　generalization　regarding　an　epoch　is　sure　to　do　that　epoch　something　less　or　something　more　than　justice。　We　may　be　sure；　then；　that　the　ideal　of　ecclesiasticism　is　not　solely　responsible　for　the　scientific　stasis　of　the　dark　age。　Indeed；　there　was　another　influence　of　a　totally　different　character　that　is　too　patent　to　be　overlookedthe　influence；　namely；　of　the　economic　condition　of　western　Europe　during　this　period。　As　I　have　elsewhere　pointed　out；＇2＇　Italy；　the　centre　of　western　civilization；　was　at　this　time　impoverished；　and　hence　could　not　provide　the　monetary　stimulus　so　essential　to　artistic　and　scientific　no　less　than　to　material　progress。　There　were　no　patrons　of　science　and