For those God foreknew he also predestined to be conformed to the image of his Son, that he might be the firstborn among many brothers and sisters. Romans 8.29
Growing into the likeness of Jesus is a legitimate - indeed necessary - Christian aspiration. As Paul implies, we acquire that aspiration as a gift of God rather than a product of our own decision. And yet, once implanted, that gift must be nurtured. "Fan into flame the gift of God" the same Paul adjured his young colleague, Timothy. Mediaeval scholars like Thomas Aquinas harnessed the insights of classical philosophers regarding how prudence functions, in their pursuit of Christian transformation, which they lauded as the ultimate expression of wisdom.
Aristotle commended prudence for the way in which it applies knowledge to experience in order to inform behaviour. Yet more is needed if such behaviour is to be constructive rather than selfish or otherwise counter-productive. And so Aristotle commends the cultivation of virtue, or "right thinking", as a necessary companion to prudence, in order to direct its activity.
Cicero taught that prudence is composed of memory, intelligence and foresight. Memory enables us to recall knowledge and experience, Intelligence helps us to make sense of them, while foresight is the ability to anticipate things before they happen. The most influential, in terms of cultivating virtue, is memory - because this is what feeds our intelligence and foresight and therefore guides our behaviour in life.
During the 12th century, a monastic teacher called Hugh elaborated on the topic of memory, in his instruction of novices at the cathedral school of St Victor in Paris. He envisioned memory as an ark in which God's faithful people are protected from the storms of life and guided into Christ-likeness. This ark is composed of many parts, to each of which is ascribed special significance which Hugh explores in great depth. Yet his focus remains on gathering his pupils disordered thoughts, so that they feed their minds in such a way as to cultivate good habits, which eventually become the virtues they require for growing into the image of Christ.