"Big Brother is watching you" is George Orwell's most famous line from his most famous book. But there's so much more to the man who gave us terms like "doublethink," "thoughtcrime" and "newspeak"; Orwell reminds us there's a connection between clarity of language and truth.

That's why he implores us to be vigilant, to be on guard for freedom, and to keep the faith: the triple faiths of decency, tolerance and humanity.

I've long been fascinated by Orwell and, in the summer of 1983, when it was still possible to meet people who knew him — from his first days to his final hours — I spent two hectic months in England, Scotland and Spain recording 75 interviews.

I made a total of 50 hours' worth of recordings which, taken together, give a detailed and nuanced picture of a man who was one of the most influential writers of our time.

I included some — but by no means all — of this unique archive in George Orwell, a Radio Biography which aired on CBC Radio 1 on Jan. 1, 1984. Recently I went back into those original recordings, to bring out insights that had never been aired before, and created a new three-hour series for CBC Radio's Ideas called The Orwell Tapes.

Orwell died in 1950. But here are five reasons why he is still very much with us today:

1. Big Brother is watching you

"Asleep or awake, working or eating, indoors or out of doors, in the bath or in bed — no escape, 'Big Brother is watching you.'" George Orwell, 1984

Orwell's most famous novel, 1984, sounded many warnings about privacy and surveillance by the state.

Is he watching you now? And if so how would you know? And even if you did are you too much in love with modern technology to care? With sensors in our pockets that track us everywhere we go are we all complicit in allowing a new era of mass surveillance?

Wikileaks founder Julian Assange once asked an assembled group: "Who here has an iPhone, who has a BlackBerry, who uses Gmail?" Most of his audience raised their hands.

"Well, you're all screwed," was his terse answer.

Fugitive Edward Snowden concurs: "A child born today will grow up with no conception of privacy at all. They'll never know what it means to have a private moment, an unrecorded, unanalyzed thought," he said, in a 2013 Christmas message posted on YouTube.

2. Power corrupts

"The creatures looked from pig to man, from man to pig … but it was impossible to say which was which." George Orwell, Animal Farm

Does changing the people in power actually change anything? Orwell's pen here was aimed at 1940's Soviet Union, but the pattern repeats and its relevance never dates. Take Ukraine in 2014, or 2004 or 1991.

As Mark MacKinnon of The Globe and Mail wrote in March 2016, of the situation in Ukraine: "There's a revolution. Hated oligarchs are overthrown. The people celebrate. Then a new batch of politicians takes power and spoils it all."

3. Encountering the 'other'

"I should like to put it on record that I have never been able to dislike Hitler," George Orwell, reviewing Mein Kampf

It took courage for Orwell to write that in March 1940 with Hitler poised to invade Britain. Demonising your enemy, to Orwell, was easy, lazy and self-defeating. He believed understanding Hitler was the best way to defeat him.

"Hitler knows that human beings don't only want comfort, safety … and in general, common sense; they also want … occasionally … struggle, self sacrifice, drums and loyalty parades," Orwell wrote.

What is the appeal of today's Hitlers? Do we demonize them too much and understand them too little?

George Orwell, centre, at the siege of Huesca during the Spanish Civil War, 1937.

4. Socialism has 9 lives

"Socialists don't claim to be able to make the world perfect. They claim to be able to make it better." George Orwell, in a December 1943 column for Tribune

After two world wars and the Great Depression, capitalism was discredited and socialism offered hope, a so-called different kind of politics.

Socialism flourished for a while but, in recent decades, it's seemed a faded relic from another era, vilified and ridiculed by many. And then Bernie Sanders and U.K. Labour Party Leader Jeremy Corbyn came along and Orwell's ideas and ideals are alive again, back on centre stage.

5. Don't shoot the messenger

"If liberty means anything at all, it means the right to tell people what they don't want to hear." George Orwell, preface to Animal Farm

Speaking truth to power is as dangerous and difficult today as it ever was. In 2015 Amnesty International supporters across the world wrote 3.7 million letters, messages, emails and tweets in aid of prisoners of conscience — people jailed for telling someone in power what they didn't want to hear or to be heard by others.