They aren't. They are more like Yin and Yang. They are intertwined - each feeds the other. They are like left foot and right foot - each allows the other to progress.
Here's a story that shows how.
The Colombia business unit of a big multinational was going through a major re-organisation. We helped them to "learn before" this exercise (which turned out to run very smoothly) and afterwards we captured their knowledge, and the knowledge from others that we had captured on their behalf, in a "knowledge asset"; a classic Codification step. As always, the knowledge asset was careful to "keep the name with the knowledge", so the knowledge was not anonymous, but was credited to individuals.
About a year later, the Venezuela business unit needed to go through a similar restructuring, and began to do their own "learning before".
Venezuela first began to access knowledge by working their personal networks, and calling people in Colombia that they just "happened to know". But before long, one of the Colombians told them about the knowledge asset and sent them the web address.
Now Venezuela had full access to the knowledge of the whole company.
Initially the 15 top-level guidelines were the most useful part of the knowledge asset, as it gave Venezuela and overview of the things they needed to consider. The "links to people" allowed Venezuela to target the correct people to call for further details; many of them in Colombia, but other people around the company as well.
As Venezuela went further into their exercise, they went further into the detail of the knowledge asset, and started to use the check-lists and artefacts. Venezuela were able to complete their restructuring in seven weeks, where it had taken Colombia three months.
The codified knowledge within the asset had facilitated socialisation, and the combination of the two reduced the time of the exercise by over 40%.