What actually constitutes a 'Dive'?

I was having a conversation with the old man the other week about diving and what actually consitutes a dive

My old man is in his 70s and has been a player and fan since he was old enough to walk. He played for the armed forces and was a tricky pacey winger (sdo he says)

As a fan he has a pretty unique attitude to which team he follows. He's never really tagged himself to one club but choose to support the local team of whereever he lived at the time. He doesn't go to games anymore but in his time he's supported Leeds Oldham United Hull (all because he lived there at some point) so he has no bias whatsoever when he talks about who is diving and who is not

He always maintains a clever defender will illegally put a striker off if he thinks he can get away with it but an even more clever attacker will punish the defender for it.

Furthermore, and we have heard this said many a time, that it takes very little contact to take down a footballer running at full flight.

The most controversial belief of the old man though is the art of choosing when to go down, When he played the game, he said if he knew a challenge was coming, then he would decide when and how to go down and not leave it up to his opponent to make that decision. That way, it reduced the risk of injury significantly

Finally, there is the 'he left his foot in deliberately' argument. My Dad's take is that again, a clever defender will know he is interfeering with a run yet giving the attacker enough time to jump out of the way of a challenge. The attacker is impeded still yet no foul is awarded (more often than not). The clever attacker will make sure he punishes the infringement my making sure there is contact and again choosing the way to actually go down

The one area he is totally against though and insists as a ref, he would not give the foul, is that the player going down does some exagerated theatrical fling to the floor and rolls around for 5 minutes. That, just like the rest of us, he cannot do with

I have deliberatly not given any player examples because the thread would just decend into a wumfest and the article is really about what is a dive as opposed to who is a diver but I don't have a problem if you need to use an example link to get a point across but let's keep it sensible.

So, Is the old man going senile of has he got a point or two?