contribute　to　render　it　altogether　impossible　that　they　who　take
  the　field　should　maintain　themselves　at　their　own　expense。　Those
  two　causes　are；　the　progress　of　manufactures；　and　the　improvement
  in　the　art　of　war。
  Though　a　husbandman　should　be　employed　in　an　expedition；
  provided　it　begins　after　seed…time　and　ends　before　harvest；　the
  interruption　of　his　business　will　not　always　occasion　any
  considerable　diminution　of　his　revenue。　Without　the　intervention
  of　his　labour；　nature　does　herself　the　greater　part　of　the　work
  which　remains　to　be　done。　But　the　moment　that　an　artificer；　a
  smith；　a　carpenter；　or　a　weaver；　for　example；　quits　his
  workhouse；　the　sole　source　of　his　revenue　is　completely　dried　up。
  Nature　does　nothing　for　him；　he　does　all　for　himself。　When　he
  takes　the　field；　therefore；　in　defence　of　the　public；　as　he　has
  no　revenue　to　maintain　himself；　he　must　necessarily　be　maintained
  by　the　public。　But　in　a　country　of　which　a　great　part　of　the
  inhabitants　are　artificers　and　manufacturers；　a　great　part　of　the
  people　who　go　to　war　must　be　drawn　from　those　classes；　and　must
  therefore　be　maintained　by　the　public　as　long　as　they　are
  employed　in　its　service。
  When　the　art　of　war；　too；　has　gradually　grown　up　to　be　a
  very　intricate　and　complicated　science；　when　the　event　of　war
  ceases　to　be　determined；　as　in　the　first　ages　of　society；　by　a
  single　irregular　skirmish　or　battle；　but　when　the　contest　is
  generally　spun　out　through　several　different　campaigns；　each　of
  which　lasts　during　the　greater　part　of　the　year；　it　becomes
  universally　necessary　that　the　public　should　maintain　those　who
  serve　the　public　in　war；　at　least　while　they　are　employed　in　that
  service。　Whatever　in　time　of　peace　might　be　the　ordinary
  occupation　of　those　who　go　to　war；　so　very　tedious　and　expensive
  a　service　would　otherwise　be　far　too　heavy　a　burden　upon　them。
  After　the　second　Persian　war；　accordingly；　the　armies　of　Athens
  seem　to　have　been　generally　composed　of　mercenary　troops；
  consisting；　indeed；　partly　of　citizens；　but　partly　too　of
  foreigners；　and　all　of　them　equally　hired　and　paid　at　the　expense
  of　the　state。　From　the　time　of　the　siege　of　Veii；　the　armies　of
  Rome　received　pay　for　their　service　during　the　time　which　they
  remained　in　the　field。　Under　the　feudal　governments　the　military
  service　both　of　the　great　lords　and　of　their　immediate　dependants
  was；　after　a　certain　period；　universally　exchanged　for　a　payment
  in　money；　which　was　employed　to　maintain　those　who　served　in
  their　stead。
  The　number　of　those　who　can　go　to　war；　in　proportion　to　the
  whole　number　of　the　people；　is　necessarily　much　smaller　in　a
  civilised　than　in　a　rude　state　of　society。　In　a　civilised
  society；　as　the　soldiers　are　maintained　altogether　by　the　labour
  of　those　who　are　not　soldiers；　the　number　of　the　former　can　never
  exceed　what　the　latter　can　maintain；　over　and　above　maintaining；
  in　a　manner　suitable　to　their　respective　stations；　both
  themselves　and　the　other　officers　of　government　and　law　whom　they
  are　obliged　to　maintain。　In　the　little　agrarian　states　of　ancient
  Greece；　a　fourth　or　a　fifth　part　of　the　whole　body　of　the　people
  considered　themselves　as　soldiers；　and　would　sometimes；　it　is
  said；　take　a　field。　Among　the　civilised　nations　of　modern　Europe；
  it　is　commonly　computed　that　not　more　than　one…hundredth　part　of
  the　inhabitants　in　any　country　can　be　employed　as　soldiers
  without　ruin　to　the　country　which　pays　the　expenses　of　their
  service。
  The　expense　of　preparing　the　army　for　the　field　seems　not　to
  have　become　considerable　in　any　nation　till　long　after　that　of
  maintaining　it　in　the　field　had　devolved　entirely　upon　the
  sovereign　or　commonwealth。　In　all　the　different　republics　of
  ancient　Greece；　to　learn　his　military　exercises　was　a　necessary
  part　of　education　imposed　by　the　state　upon　every　free　citizen。
  In　every　city　there　seems　to　have　been　a　public　field；　in　which；
  under　the　protection　of　the　public　magistrate；　the　young　people
  were　taught　their　different　exercises　by　different　masters。　In
  this　very　simple　institution　consisted　the　whole　expense　which
  any　Grecian　state　seems　ever　to　have　been　at　in　preparing　its
  citizens　for　war。　In　ancient　Rome　the　exercises　of　the　Campus
  Martius　answered　the　same　purpose　with　those　of　the　Gymnasium　in
  ancient　Greece。　Under　the　feudal　governments；　the　many　public
  ordinances　that　the　citizens　of　every　district　should　practise
  archery　as　well　as　several　other　military　exercises　were　intended
  for　promoting　the　same　purpose；　but　do　not　seem　to　have　promoted
  it　so　well。　Either　from　want　of　interest　in　the　officers
  entrusted　with　the　execution　of　those　ordinances；　or　from　some
  other　cause；　they　appear　to　have　been　universally　neglected；　and
  in　the　progress　of　all　those　governments；　military　exercises　seem
  to　have　gone　gradually　into　disuse　among　the　great　body　of　the
  people。
  In　the　republics　of　ancient　Greece　and　Rome；　during　the
  whole　period　of　their　existence；　and　under　the　feudal　governments
  for　a　considerable　time　after　their　first　establishment；　the
  trade　of　a　soldier　was　not　a　separate；　distinct　trade；　which
  constituted　the　sole　or　principal　occupation　of　a　particular
  class　of　citizens。　Every　subject　of　the　state；　whatever　might　be
  the　ordinary　trade　or　occupation　by　which　he　gained　his
  livelihood；　considered　himself；　upon　all　ordinary　occasions；　as
  fit　likewise　to　exercise　the　trade　of　a　soldier；　and　upon　many
  extraordinary　occasions　as　bound　to　exercise　it。
  The　art　of　war；　however；　as　it　is　certainly　the　noblest　of
  all　arts；　so　in　the　progress　of　improvement　it　necessarily
  becomes　one　of　the　most　complicated　among　them。　The　state　of　the
  mechanical；　as　well　as　of　some　other　arts；　with　which　it　is
  necessarily　connected；　determines　the　degree　of　perfection　to
  which　it　is　capable　of　being　carried　at　any　particular　time。　But
  in　order　to　carry　it　to　this　degree　of　perfection；　it　is
  necessary　that　it　should　become　the　sole　or　principal　occupation
  of　a　particular　class　of　citizens；　and　the　division　of　labour　is
  as　necessary　for　the　improvement　of　this；　as　of　every　other　art。
  Into　other　arts　the　division　of　labour　is　naturally　introduced　by
  the　prudence　of　individuals；　who　find　that　they　promote　their
  private　interest　better　by　confining　themselves　to　a　particular
  trade　than　by　exercising　a　great　number。　But　it　is　the　wisdom　of
  the　state　only　which　can　render　the　trade　of　a　soldier　a
  particular　trade　separate　and　distinct　from　all　others。　A　private
  citizen　who；　in　time　of　profound　peace；　and　without　any
  particular　encouragement　from　the　public；　should　spend　the
  greater　part　of　his　time　in　military　exercises；　might；　no　doubt；
  both　improve　himself　very　much　in　them；　and　amuse　himself　very
  well；　but　he　certainly　would　not　promote　his　own　interest。　It　is
  the　wisdom　of　the　state　only　which　can　render　it　for　his　interest
  to　give　up　the　greater　part　of　his　time　to　this　peculiar
  occupation：　and　states　have　not　always　had　this　wisdom；　even　when
  their　circumstances　had　become　such　that　the　preservation　of
  their　existence　required　that　they　should　have　it。
  A　shepherd　has　a　great　deal　of　leisure；　a　husbandman；　in　the
  rude　state　of　husbandry；　has　some；　an　artificer　or　manufacturer
  has　none　at　all。　The　first　may；　without　any　loss；　employ　a　great
  deal　of　his　time　in　martial　exercises；　the　second　may　employ　some
  part　of　it；　but　the　last　cannot　employ　a　single　hour　in　them
  without　some　loss；　and　his　attention　to　his　own　interest
  naturally　leads　him　to　neglect　them　altogether。　These
  improvements　in　husbandry　too；　which　the　progress　of　arts　and
  manufactures　necessarily　introduces；　leave　the　husbandman　as
  little　leisure　as　the　artificer。　Military　exercises　come　to　be　as
  much　neglected　by　the　inhabitants　of　the　country　as　by　those　of
  the　town；　and　the　great　body　of　the　people　becomes　altogether
  unwarlike。　That　wealth；　at　the　same　time；　which　always　follows
  the　improvements　of　agriculture　and　manufactures；　and　which　in
  reality　is　no　more　than　the　accumulated　produce　of　those
  improvements；　provokes　the　invasion　of　all　their　neighbours。　An
  industrious；　and　upon　that　account　a　wealthy　nation；　is　of　all
  nations　the　most　likely　to　be　attacked；　and　unless　the　state
  takes　some　new　measures　for　the　public　defence；　the　natural
  habits　of　the　people　render　them　altogether　incapable　of
  defending　themselves。
  In　these　circumstances　there　seem　to　be　but　two　methods　by
  which　the　state　can　make　any　tolerable　provision　for　the　public
  defence。
  It　may　either；　first；　by　means　of　a　very　rigorous　police；
  and　in　spite　of　the　whole　bent　of　the　interest；　genius；　and
  inclinations　of　the　people；　enforce　the　practice　of　military
  exercises；　and　oblige　either　all　the　citizens　of　the　military
  age；　or　a　certain　number　of　them；　to　join　in　some　measure　the
  trade　of　a　soldier　to　whatever　other　trade　or　profession　they　may
  happen　to　carry　on。