Summary
Epicurus begins by declaring that philosophy is appropriate at every age. The young should not postpone it, and the old should not become weary of it, because seeking wisdom is inseparable from seeking happiness and health of soul.
Young and old benefit in different but connected ways. Older people can remain renewed by gratitude for goods already experienced, while younger people can develop steadiness towards the future. Both should practise the teachings that produce happiness.
The first teaching concerns the gods. A divine being should be understood as immortal and blessed. Any belief that makes a god disturbed, vindictive or inconsistent with blessedness should be rejected. Epicurus maintains that gods exist but criticises popular representations of their involvement in human rewards and punishments.
He then turns to death. Good and evil depend upon sensation, and death removes sensation. Understanding this allows people to enjoy mortal life without demanding endless duration. The desire for immortality loses its power when death is recognised as something the person never experiences.
Fear of death is irrational because it produces pain in anticipation of a condition that cannot cause pain when it arrives. While people are alive, death is absent; when death is present, they are no longer there as experiencing subjects.
The wise person therefore neither despises life nor fears its ending. The comparison with food shows that a pleasant portion is preferable to mere quantity. A worthwhile life is not measured only by length but by the character of the time enjoyed.
Epicurus rejects the view that the young should learn to live while the old should prepare only to die. The same understanding teaches both living and dying well. He also criticises claims that non-existence is preferable when those making them do not act consistently with their assertion.
The future is neither entirely controlled by us nor completely independent of us. We should not rely upon future events as certain, but we should not despair as though action made no difference.
Desires are divided into categories. Some are natural and necessary, some natural but not necessary, and some groundless. Among necessary desires, certain ones support happiness, freedom from bodily discomfort or life itself.
Clear classification enables choices to be directed towards health of body and tranquillity of mind. These conditions form the goal of the blessed life. When pain and fear are absent, the person is not driven by an imagined deficiency towards endless acquisition.
Epicurus calls pleasure the beginning and end of a happy life because feeling supplies the basic standard through which benefits and harms are recognised. Nevertheless, not every pleasure should be selected. An immediate enjoyment may be refused when it produces greater trouble.
Likewise, not every pain should be avoided. A person may reasonably accept discomfort when it leads to a more important or durable pleasure. Practical judgement compares advantages and disadvantages rather than following the nearest sensation blindly.
Self-sufficiency is valuable because it reduces vulnerability. Epicurus does not insist that people must always possess little. He wants them to remain content when little is available. Luxury is enjoyed most freely by someone who does not require it.
Natural needs are generally easy to satisfy, while empty desires are difficult because they have no stable limit. Bread and water become intensely pleasant when they remove hunger and thirst. Habituation to simplicity supports health, readiness and freedom from fear of fortune.
Epicurus explicitly denies that pleasure means drinking, revelry, sexual excess or uninterrupted luxury. The pleasant life is freedom from bodily pain and mental trouble. It is produced through sober reasoning that examines every choice and removes disturbing false beliefs.
Prudence is named the greatest good and the source of the virtues. It shows that pleasure cannot be securely achieved without honourable and just conduct. In turn, a prudent and just life is inseparable from genuine pleasure.
The wise person holds fitting beliefs about the gods, does not fear death, understands that natural goods have attainable limits and recognises that many evils are brief or manageable.
Epicurus rejects total fatalism. Some things happen by necessity, some by chance and some through human agency. Responsibility, praise and blame apply to actions that arise through agency rather than to what is unavoidable.
Chance may create opportunities for great good or evil, but it is not a divine ruler of life. A wise decision retains value even if fortune prevents its success. Epicurus prefers good judgement accompanied by misfortune to foolishness accompanied by prosperity.
The letter ends with an instruction to practise these principles continuously, alone and with a like-minded companion. Such exercise will reduce disturbance and make mortal life resemble divine blessedness through its participation in stable and enduring goods.