 Aquinas firmly holds the Platonic-Aristotelian theses (i) of the connexio virtutum: that to have any of the virtues in its full and proper form one must have all of them, and (ii) of the governing and shaping role of (the good of) practical reasonableness (bonum rationis), that is, of the intellectual and moral virtue of prudentia. For some indication why, see 4.4 below..