The Codex of Ultimate Wisdom
Now, where is the Codex Shrine? It is on an island East of Blackthorn's Castle, the same one where the Shrine of Humility is. The Codex Shrine is on the southernmost part of the island. Get there by skiff and land in the south. There's no pier. In order to access the Shrine, you need both the Lockpick and the Skull Key. The Codex of Ultimate Wisdom will tell you about all the virtues, if you said all the proper mantras at the shrines.
The Eight Virtues
Compassion: "It is a lonely life that owes its pleasure to the pain of others."
Second pilgrimage to the Shrines
Now that you learned about the Eight Virtues, you should practice them in real life. But this is just a videogame walkthrough, so let's keep on with the videogame.
Shrine of Humility
If you visit the Shrines again, your attributes will be raised. Circumnavigate the island of the Codex and you'll get to the gulf of the Shrine of Humility. Talk to the Shrine, and you will humbly keep your attributes.
Shrine of Honesty
Sail North, circumnavigate Verity Isle (with Moonglow and the Lycaeum), and continue North. Land in the next island and talk at the Shrine of Honesty. Your Intelligence will go up by 1.
Shrine of Sacrifice
Circumnavigate the island to the North and land on Britannia mainland. Walk west to Sin'Vraal's hut, then continue North to the Shrine of Sacrifice. Talk to the Shrine, and both your Strength and Dexterity will go up by 1.
Shrine of Compassion
From the Shrine of Sacrifice go West and follow the long road to Britain. Before getting to Britain, take the East road at the fork and get to the Shrine of Compassion. Talk to the Shrine and your Dexterity will go up by 1.
Shrine of Justice
Trace your steps to the Magic Shop in Yew, cross the bridge North and follow the river North-East. Cross the bridge you will meet, walk East and cross another bridge. Talk to the Shrine, and both your Strength and Intelligence will go up by 1.
Shrine of Honor
Now you have to trace your steps back to Yew and walk South to Trinsic. Continue South from Trinsic, and turn West at the fork to get to the Shrine. Talk to the Shrine, and both your Intelligence and Dexterity will go up by 1.
Shrine of Valor
From the Shrine of Honor, walk South-West until you get to the seaside. From there sail South and get to Jhelom. Follow the coast and you'll get to the Shrine of Valor. Talk to the Shrine and your Strength will go up by 1.
Shrine of Spirituality
Skara Brae is far away North of Jhelom, but you don't have to get there. In fact, all the Moongates appear at the same time at sunset. Jhelom Moongate is on the promontory just south of Naughty Nomaan's weapon shop. Wait for the right time of the night and step into the Moongate. Talk to the Shrine, and your Strength, Intelligence and Dexterity will all go up by 1. When you get back to Britannia you can discard the watch because it is not anymore necessary.
Now all the attributes of the Avatar and his three companions have been raised by 4, and you're ready to explore the remaining six Dungeons. Before that, though, I'd suggest to buy as many reagents and yellow potions as possible, and feel free to use magic at will from now on.