I have just returned from a 6 month break to a much improved system that I like tons better than the old one for both playability and enhancements. The question I have is about Toughness Enhancements.

Are the totals from each level of the toughness enhancements Cumulative or do they replace the prior one?
i.e.
Dwarven Toughness I replaces the standard +3 hp at 1st level with a +5.
Dwarven Toughness II replaces the it with a +10 BUT does it replace DT I's +5 for a +7 hp increase
10
-3
7



--OR--

Does it add the 5 from Dwarven Toughness I and the 10 from Dwarven Toughness II for a total increase of +12hp?

5
+10
15
-3
12

--OR--
Does it add the increase for Dwarven Tough I and Dwarven Toughness II together for an increase of +9hp?

5
-3
2

10
-3
7

2
+7
9


With this simple yet complex series of questions being answered, I will be able to formulate the proper build I am making for a 8Paladin/6Fighter. I greatly appreciate any help on this subject that everyone can supply.