There is two samma ditthi. One is lokiya where one can know the four noble truths but still unaware of lokuttara samma ditthi. It's like lokiya samma ditthi is shadow of lokuttara samma ditthi. Lokiya samma ditthi is hight of impermanence, 7th in number and lokuttara samma ditthi is 8th "Unborn, Uncreated, Real, the Goal".
The real eightfold path starts with ditthi of 8th.
Here samma ditthi is like "The seer, the object that seen and the activity of seeing are merged and universe exist not".
Remember Buddha worked really hard to reach to Amataphala or fruit immortal, to become one with it.
He said, "Monks if there is not this unborn, undecaying state , then this born, decayed individual would have no hope"
In one sentence, to union with the unborn is true goal, Nirvana.