Harold Wilson used to say the Labour Party was a moral crusade or it was nothing. During the Tony Blair years, it was pretty clear that it had become nothing. Yet in one passage of today's speech, Mr Brown restored the moral purpose that has been missing from the party for so long.
"And why do we always strive for fairness? Not because it makes good soundbites. Not because it gives good photo opportunities. Not because it makes for good PR. No. We do it because fairness is in our DNA. It's who we are - and what we're for. It's why Labour exists. It's our first instinct, the soul of our party. It's why when things get tough, we get tougher."
Although the pundits will doubtless focus on his clever two-in-one put-down of the two Davids - "This is no time for a novice" - this, for me, was the key message of the speech, a reminder to the country that this party is about more than simply a desire to stay in power for as long as possible.
The message was underlined, near the very end of the speech, by Mr Brown's use of the phrase "United we are a great movement."
The words "This Great Movement Of Ours" or "TGMOO" used to be practically obligatory in Labour leader's speeches in the pre-Blair days, but references to Labour as a "movement" went dramatically out of fashion during the NuLab era, presumably because, like "moral crusade," the word implies some higher purpose. The idealists among us will be pleased to see it back again.