Treating，inthefirstpart，oftheinfluenceofexternalconditions，ofrace，andofcultureonlibertyinthiswidersense，he
proceedstodivideallproductiveeffortintotwogreatclasses，accordingastheactionisexercisedonthingsoronmen，and
censurestheeconomistsforhavingrestrictedtheirattentiontotheformer。Hestudiesinhissecondandthirdparts
respectivelytheconditionsoftheefficiencyofthesetwoformsofhumanexertion。Intreatingofeconomiclife，strictlyso
called，heintroduceshisfourfolddivisionofmaterialindustry，inpartadoptedbyJ。S。Mill，as\"（1）extractive，（2）voiturière，