I was watching a procession of French limousines disgorging a procession of African presidents when I noticed that a colleague of mine, a veteran observer of summits, had started compiling a list of how many kisses each visiting president was getting from Jacques Chirac.
You can tell a lot from body language, he explained, especially French body language.
President Chirac's welcome to the Zimbabwean leader was laden with messages
I started studying President Chirac more closely and realised my friend was right. Most of the African leaders got three kisses - French-style, right cheek, nod, left cheek, nod, right.
But some of them only got two and some got four. There was, literally, a pecking order.
Up for four kisses were special friends of France or countries that for one reason or another fitted the French view of the world.
The presidents of the West African states of Senegal and Ghana got the full four kisses each. Both countries have recently held thoroughly democratic elections.
The theory did not hold good all the way. The king of Morocco got four pecks and a firm squeeze of the shoulders. The royal dynasty is not renowned for its democratic tendencies, but is a friend of France.
Further down the scale the leader of Equatorial Guinea only got two kisses. Perhaps one was taken off for human rights abuses and one off for bad governance? We shall never know.
But the body language between the French leader and his counterpart from the central African state of Rwanda was unmistakable.
The two men are both tall, very tall, and when they approached each other they stood ramrod straight and shook hands stiffly - and no kisses at all.
No kisses for Mugabe
But there was worse to come in the body language stakes. The most controversial guest in Paris was President Robert Mugabe of Zimbabwe.
Despite a European Union travel ban on him and his ministers, France obtained a waiver for Mr Mugabe to come here.
Chirac: A master of diplomatic body language
The official French line was that it's better to talk face-to-face about human rights abuses than to sweep them under the carpet.
There are some more cynical explanations doing the rounds. Like speculation that France checked out Zimbabwe's appalling diplomatic relations with Britain and decided to step in for whatever political and economic advantage it could grab.
But having Mr Mugabe here was one thing. Being filmed on French television in Mr Mugabe's company is a bit more touchy.
France after all, is the land of liberty and fraternity, neither of which are in strong supply in Zimbabwe, and French voters could, potentially, spot the contradiction.
The solution - body language again.
Mr Chirac's right hand shook Mr Mugabe's, but in a limp sort of way, and the Frenchman held his head back.
The summitry could be overshadowed by military action
No question of any kisses at all. The body language was completed by Mr Chirac using his left hand to usher Mr Mugabe along, out of camera-shot, as soon as possible.
This was masterful diplomatic stuff. President Chirac wasn't exactly rude, but he wasn't exactly welcoming either.
He somehow got two messages out at once. The first message was for France - we're concerned about the human rights abuses in Zimbabwe.
The second message was for Africa - we are ready to talk. And it turned out that the second message was crucial to the main purpose of holding this Franco-African summit which was to become clear later in the day, namely, diplomacy over Iraq.
Music to Chirac's ears
A common statement emerged from the summit, via the French organisers, saying that all the participants agreed with - you've got it - the French position on Iraq.
Support the weapons inspectors, urge Iraq to co-operate fully and actively, use force only as a last resort. There is, the declaration concluded, an alternative to war.
By chance three of the countries present in Paris - Angola, Guinea and Cameroon - are currently on the UN Security Council, and their votes could be crucial if and when a second UN resolution is sought.
But the overall message was music to Chirac's ears - Africa agrees with France.
Of course, all this talking and summitry and body language could easily be overtaken by military action.
But no-one can say France hasn't been active in kissing its way along the diplomatic path.