- The goal of life is eudaimonia and mental clarity or lucidity (ἁτυφια) - freedom from smoke (τύφος) which signified ignorance, mindlessness, folly, and conceit.
- Eudaimonia is achieved by living in accord with Nature as understood by human reason.
- Arrogance (τύφος) is caused by false judgments of value, which cause negative emotions, unnatural desires, and a vicious character.
- Eudaimonia, or human flourishing, depends on self-sufficiency (αὐτάρκεια), equanimity, arete, love of humanity, parrhesia and indifference to the vicissitudes of life (ἁδιαφορία).
- One progresses towards flourishing and clarity through ascetic practices (ἄσκησις) which help one become free from influences – such as wealth, fame, and power – that have no value in Nature. Examples include Diogenes' practice of living in a tub and walking barefoot in winter.
- A cynic practices shamelessness or impudence (Αναιδεια) and defaces the nomos of society; the laws, customs, and social conventions which people take for granted.
Thus a cynic has no property and rejects all conventional values of money, fame, power and reputation. A life lived according to nature requires only the bare necessities required for existence, and one can become free by unshackling oneself from any needs which are the result of convention. The cynics adopted Heracles as their hero, as epitomizing the ideal cynic. Heracles "was he who brought Cerberus, the hound of Hades, from the underworld, a point of special appeal to the dog-man, Diogenes." According to Lucian, "Cerberus and Cynic are surely related through the dog."
The cynic way of life required continuous training, not just in exercising judgments and mental impressions, but a physical training as well:
[Diogenes] used to say, that there were two kinds of exercise: that, namely, of the mind and that of the body; and that the latter of these created in the mind such quick and agile impressions at the time of its performance, as very much facilitated the practice of virtue; but that one was imperfect without the other, since the health and vigour necessary for the practice of what is good, depend equally on both mind and body.
None of this meant that a cynic would retreat from society. Cynics were in fact to live in the full glare of the public's gaze and be quite indifferent in the face of any insults which might result from their unconventional behaviour. The cynics are said to have invented the idea of cosmopolitanism: when he was asked where he came from, Diogenes replied that he was "a citizen of the world, (kosmopolitês)."
The ideal cynic would evangelise; as the watchdog of humanity, they thought it their duty to hound people about the error of their ways. The example of the cynic's life (and the use of the cynic's biting satire) would dig-up and expose the pretensions which lay at the root of everyday conventions.
Although cynicism concentrated solely on ethics, cynic philosophy had a major impact on the Hellenistic world, ultimately becoming an important influence for Stoicism. The Stoic Apollodorus writing in the 2nd century BC stated that "Cynicism is the short path to virtue."