2 , ▁where ▁C allen ▁defines ▁temperature ▁as ▁the ▁reci pro cal ▁of ▁the ▁derivative ▁of ▁entropy ▁with ▁respect ▁to ▁internal ▁energy ▁then ▁shows , ▁using ▁the ▁post ul ates , ▁that ▁this ▁definition ▁is ▁consistent ▁with ▁our ▁intu ition . ▁While ▁Z em ans ky ▁and ▁D itt man ▁cover ▁the ▁first ▁law ▁of ▁therm od ynam ics ▁empir ically , ▁C allen ▁simply ▁assumes ▁the ▁existence ▁of ▁the ▁internal ▁energy ▁function ▁the ▁inv okes ▁the ▁conserv ative ▁nature ▁of ▁inter - atomic ▁forces . ▁Where as ▁Z em ans ky ▁and ▁D itt man ▁treated ▁the ▁second ▁law ▁of ▁therm od ynam ics ▁using ▁heat ▁engines ▁and ▁simply ▁state ▁the ▁Cla us ius ▁and ▁Kel vin ▁form ulations ▁of ▁it , ▁in ▁C allen ' s ▁book , ▁the ▁second ▁law ▁is ▁contained ▁within ▁the ▁post ul ates . ▁Scott ▁was ▁uns ure ▁which ▁approach ▁is ▁more ▁understand able ▁for ▁students . ▁In ▁general , ▁Z em ans ky ▁and ▁D itt man ▁employed ▁an ▁empir ical ▁approach ▁while ▁that ▁of ▁C allen ▁is ▁ded uct ive . ▁Scott ▁op ined ▁that ▁Z em ans ky ▁and ▁D itt man ' s ▁book ▁is ▁more ▁suitable ▁for ▁beginning ▁students ▁while ▁C allen ' s ▁is ▁more ▁appropriate ▁for ▁an ▁advanced ▁course ▁or ▁as ▁a ▁reference . ▁ ▁Ed itions ▁ ▁See ▁also ▁▁▁ ▁List ▁of ▁text books ▁in ▁therm od ynam ics ▁and ▁statistical ▁mechan ics ▁ ▁References ▁▁ ▁Category : Th erm od ynam ics ▁literature ▁Category : 1 9