One thing that bugs me about the rules for writing books is how incestuous it can be.
You can have a small group of people each with Magic Theory 3 write a book on MT. They can read each others work and then as they level up their skill in MT, they can write another book each. Whilst this has some limits, it's essentially creating knowledge out of nothing. They are just parroting back what they have already learned and generating new knowledge out of thin air.
So instead imagine if:
When you write a Tractatus you get a -2 penalty by default.
This penalty can be ignored if:
- You have studied from the appropriate source of Vis last season.
- You got a triple explosion or a triple botch on the relevant ability last season (Mostly for Mundane skills, you can learn almost as much from massive failure as success.)
- You practiced that ability in the previous season.
- You performed and experiment and got a successful discovery roll last season. (This grants an additional +2 to the quality)