The influence of Francis Bacon was also profound. Bacon, and indeed Hobbes, held the conviction that mathematics and the senses must be the basis of all rational sciences. This passion for accuracy led Petty to famously declare that his form of science would only use measurable phenomena and would seek quantitative precision, rather than rely on comparatives or superlatives, yielding a new subject that he named "political arithmetic". Petty thus carved a niche for himself as the first dedicated economic scientist, amidst the merchant-pamphleteers, such as Thomas Mun or Josiah Child, and philosopher-scientists occasionally discussing economics, such as John Locke.