The dialogue begins with Socrates returning from the military campaign at Potidaea and visiting a local palaestra, where he is introduced to Charmides, a youth renowned for both his physical beauty and his exceptional temperance. When Charmides complains of a morning headache, Socrates offers a cure involving a medicinal leaf accompanied by a special charm learned from a Thracian king. This charm introduces the foundational premise that the body cannot be healed without first tending to the soul through wise words, which implant temperance.
Eager to test whether Charmides truly possesses the temperance attributed to him by his guardian Critias, Socrates asks him to define the virtue. Charmides first suggests that temperance is a kind of quietness in walking and daily life. Socrates demonstrates through numerous examples from physical training and education that quickness and agility are frequently superior to quietness, rendering this initial definition inadequate.
Charmides then proposes that temperance is modesty, but Socrates points out that certain authorities have declared modesty unsuitable for the needy, proving it cannot be universally good, whereas temperance is always a good thing. Prompted by Critias, Charmides offers a third definition: temperance is doing one's own business. Socrates subjects this to critical analysis, comparing it to the work of craftsmen who perform tasks that affect others and arguing that a well-ordered state would not function if everyone were restricted solely to manual tasks meant strictly for themselves.
At this point, Critias intervenes to defend the definition, arguing that making things is distinct from doing good work, and eventually proposes a fifth definition borrowed from the Delphic maxim: temperance is self-knowledge, or a science of what one knows and does not know. Socrates questions how a science can take itself as its own object without a distinct subject matter, comparing it to vision that sees only itself rather than visible things. Furthermore, even if such a self-referential science of knowledge were possible, Socrates questions its utility, arguing that simply knowing what one knows does not bring happiness unless it is specifically the knowledge of good and evil.
The conversation concludes without reaching a definitive philosophical account of temperance, leaving Charmides to accept that he must continue to submit to Socrates's guidance and charm daily in pursuit of true self-knowledge.
