It were good to know how much hay an acre of every sort will bear; how many cattle the same weight of each sort of hay will feed and fatten; what quantity of grain and other commodities the same acre will bear in one, three or seven years; unto what use each soil is proper; all which particulars I call intrinsic value, for there is also another value merely accidental or extrinsic.
William PettyThe method I take to do this is not yet very usual; for instead of using only comparative and superlative Words, and intellectual Arguments, I have taken the course (as a Specimen of the Political Arithmetic I have long aimed at) to express myself in Terms of Number, Weight, or Measure; to use only Arguments of Sense, and to consider only such Causes, as have visible Foundations in Nature.
William PettyAn house is of a double nature, viz., one, wherein it is a way and means of expence, the other as it is an instrument and tool of gain.
William Petty