We get all sorts of messages. From the world. From social media. From other people. From our bodies. The question–the great difficulty of life–is gathering, deciphering and deciding which of these messages to listen to and act on, and which to ignore.

One of the best translators of the Stoics, Robin Waterfield (you must read his annotated edition of Meditations), renders Marcus Aurelius’s use of the word hegemonikon as command center. Using this military metaphor, he says that we use our mental command center to receive all the messages of life and then send out our own messages to ourselves.

For instance, some urge in your body is telling you to do something. The command center decides whether this urge is good or not, whether to act on it or not. Or perhaps a strong emotional impulse is telling you to be afraid, that you have been hurt, that you should be angry–but again, the command center evaluates the intelligence that has been brought with this claim. It questions whether you have been harmed and whether anger helps the situation. It assesses whether you will regret saying or doing what you feel inclined to say or do. You are told by the world that certain things matter, that you should value this or that–and once more the command center has to check whether this aligns with the mission you have been given or the discipline you have committed to.

While some translators disagree with Waterfield’s rendering of hegemonikon, this metaphor undoubtedly captures a very important part of the essence of Stoicism. Our mind has to be in control–in command. Not our emotions, not what other people think, not the rush or stress of the moment. We have to be rational. We have to be clear. We have to be in charge–and stay in charge.

It is our training that will make it so.