Part of the problem that I am facing is how can something which cannot be a measure be used as a measure. It is not possible to measure something if it is not in some way congruent or possess what it measures. However, it does seem that something used as a measure can possess what it measure in an accidental way through another and thus is used as a measure per aliud.
Consider some failures at measure: a broken clock and Bitcoins.
A broken clock is a measure through another, that is it measure not of itself but in virtue of another. In this way we say that a broken clock is “right” twice a day. It is right because it is a measured measure. It possess time accidentally in virtue of itself already having been measured. This is seen in the construction of the clock, the face is already determined by some real motion, namely the rotation of the earth. In virtue of this real motion, the broken clock measures things, but only in an accidental way.
A Bitcoin is worthless and cannot be money. However, as the Philosopher teaches money is the measure of desire or need. Now, Bitcoins are similarly a measured measure. They are first measured by human desire. That is men irrationally desire them in their essentially worthless condition. In virtue of this, Bitcoins take on an accidental character of money and become money accidentally, that is they measure value through another. Other things are then mediately and essentially measured by that irrational desire for something worthless.
Law measure human behavior as just or unjust. An unjust law cannot be a measure in itself. However, an unjust law is a measured measure. It has an accidental character of justice in virtue of the practical judgement of the legislator. He errors in his judgement, but this allows an unjust law to take on the character of a measure of justice while in itself having no justice in itself. Like the Bitcoin, it nature as measure is accidental and grounded in the irrational judgement.