Judith Ancer: On a beautiful autumn day, Johannesburg is quietly rusting. I sit at a pavement café, sipping a cappuccino in the gentle May sun. Life may not be perfect, but at least I have my health for now, a job and a future. Around me sit others apparently of similar good health and position. Life is good. Not that you'd know it.

Listening to the conversations around me, this might be a besieged city in Libya. A woman complains bitterly to her husband about incompetent domestic help while their young children sip milk shakes. A man in a business suit bemoans the corrupt state of our government. An old man wearing a golf shirt says: "Education is finished in this country. They can't fix it."

I wonder what their children think? I wonder what they hear around the dinner table, at family occasions and on trips to school? All this negativity spreading out in waves. You hear these complaints in shopping queues, waiting for a bus, at the licensing office and everywhere else, it seems.

I remember hearing them as our airplane landed in Johannesburg from a holiday in Mauritius: South Africans dressed in beach wear suddenly rediscovering their pessimism in the long queue at passport control.

Of course, South Africa has severe problems, so let's deal with this straight away and admit that there's plenty to be infuriated and anxious about. It's unsettling when you read the crime reports printed by your local community organisation - crimes down your street or in the nearby park. It's undermining when your top cops spend more time in court defending corruption charges than doing their jobs, or the second traffic cop in a row tries to solicit a bribe from you. It's incomprehensible that more is not done to help those living in severe poverty.

But these are problems about which to be righteously angry, not pervasively pessimistic and passive. Use your righteous anger to join your local residents' association, become a councillor, vote in the upcoming local government elections, write letters, go to court and, most importantly, in your personal space, act with integrity and set an example.

Your children are watching, listening and learning from the example you set in dealing with adversity. Their involvement in their school and community might very well end up matching your involvement in the world.

Perhaps it's unfair, but when I hear from pervasive pessimists that life in South Africa is tough, I find myself wanting to say that life was also tough in England in 1914 when mothers sent their sons off to be slaughtered in the trenches of World War One, or for the businessman having a cup of morning coffee in the Twin Towers on September 9, 2001, or a family living on the Sri Lankan coast in 2004 when the tsunami struck. Bad things do happen.

I am reminded of my 102-year-old grandmother. She's now in a wheelchair and is hard of hearing, but remains one of the most resilient people I know, always full of self-deprecating humour and amusing anecdotes.

You wouldn't think that she once had to hide in a hay cart from the Cossacks, survived the Russian Revolution, the death of many of her relatives in World War Two and the premature loss of her husband.

It's normal and important to be sad sometimes, to be depressed, to lose hope for a while.

But we also owe it to our children to convey to them that life has meaning. There is meaning in the everyday joys of life, from our beautiful autumn trees to our family celebrations, to watching a funny TV show together or cuddling up in bed with a good book.

There is meaning in studying at school, building a future. There is also meaning in struggle - perhaps living means "to struggle amid a struggling world".

I believe my ideas are best summed up by Swedish filmmaker Ingmar Bergman, who wrote in his script for the movie Fanny and Alexander: "The world is a den of thieves and night is falling. Evil breaks its chains and runs through the world like a mad dog ... . No one escapes, not even our children. So it shall be. Therefore, let us be happy while we are happy. Let us be kind, generous, affectionate and good. It is necessary, and not at all shameful, to take pleasure in the little world. Good food, gentle smiles, fruit trees in bloom, waltzes."

Ancer is a Johannesburg-based psychologist