Regarding the point of this thread (?), particular Mason Ganney's most   
recent note, any of us can pursue our various interests. Mine was and   
remains not who discovered "factors of production," or some arguable   
(careless) antecedent, as if this word "factor" were something like the   
last word (or concept) in the science, but when it was that "economists"   
began to think of production in terms specifically and precisely of   
"factors," a term in the 19th-century still of common mathematical,   
commercial, legal, and maybe other kinds of use and significance--and then   
when it was that they developed their own profession's definition of the   
word, until they decided to use "inputs."  
  
John Womack