Liberum arbitrium Latin expression meaning ‘free judgment’, often used to refer to medieval doctrines of free choice or free will. It appears in the title of Augustine’s seminal work De libero arbitrio voluntatis (usually translated ‘On the Free Choice of the Will’) and in many other medieval writings (e.g., Aquinas, in Summa theologiae I, asks ‘whether man has free choice [liberum arbitrium]’). For medieval thinkers, a judgment (arbitrium) ‘of the will’ was a conclusion of practical reasoning – ‘I will do this’ (hence, a choice or decision) – in contrast to a judgment ‘of the intellect’ (‘This is the case’), which concludes theoretical reasoning. See also FREE WILL PROBLEM , PRACTICAL REASONIN. R.H.K.