Thomas Aquinas, in his famous argument on human law, classified the process of sentencing as an art, as opposed to a science. Human law, he argued, or at least good human law, “has the force of law in that it flows from natural law”. And yet, Aquinas further maintained that “commands can be traced to natural law in two ways; one, drawn deductively like conclusions from premises; two, grounded on it like constructional implementations of general directives. The first process is like that of the sciences. … The second process is like that of the arts where a special shape is given to a general idea, as when an architect determines that a house should be in this or that style”. Hence while a proposition such as “you must not commit murder” can be deduced from “you must not commit harm”, no similar deduction can determine the appropriate punishment for the crime: “Natural law pronounces that crime has to be punished without deciding whether this or that should be the penalty; the punishment selected is like a determinate form given to natural law”, concludes Aquinas.