Prudence is the mold and mother of all the virtues. The degree to which you are prudent determines in a sense the degree to which you are Brave, Just, Temperate. That is to say, the degree to which you can see (prudence is an intellectual virtue, so see is an analogy for practical insight so to speak) is the degree to which you know how to navigate a particular situation or reality in terms of the application of virtue.
Many people invert the meaning of prudence to mean protection of self, calculation in order to bolster oneself....rather than the traditional definition. This leads to calling vice prudent and virtue imprudent. But this is a definitional issue, which showcases a fundamental change in attitude regarding the self in relationship to reality, the world etc.
Being Precedes truth. And Truth precedes goodness.
Being an intellectual virtue, concerned with particulars, Prudence sees being and supplies the necessary truth to actions, so that, being chosen by the will, a person can choose the Good, which is accordance with the truth and with being.
Prudence is a necessary gatekeeper, although it is actually a habit of mind, between Reality and a good action. There fore it is necessary.
Prudence is the precondition for any virtue. It is the precondition for, and is synonymous with good action. Prudence requires receptivity to reality (i.e. Reason) and Reality itself (i.e. reality which reveals itself to me.
You can have no good action without prudence.