Teaching is initiating the unschooled citizens on the borders of your empire in your official school of thought in order to expand small corners of your civilization not already swallowed up from the uniform territorial expansion brought on by Civilization Value increases thorugh Worship. Teaching is useful for gerrymandering your borders just enough to snatch up a useful Collection Point (which may be entered only if it falls within the boundaries of your civilization), covering another City if you're hungry for taxes, or pushing back the influence of an encroaching civilization.
Teaching can be initiated only within the borders of your empire, but its effect will range beyond the Plot in which it was started (as long as this Plot is close to the border). The effectiveness of a Teaching session depends on the Teach value of the Priest who begins it.
Aside from helping a player expand her or his empire, Teaching is also one of the two ways (the other being Worship) that a Priest can gain experience points to jump levels. So put away your sword for a while, pull out those books, and start proselytizing the heathens in your far lands.
How to Teach Edit
1. Click a Plot (piece of land) on the border of your Civilization (should be bright green).
2. Click the "Teach" button on the interface that pops up.
3. Select a Priest from the list of idle units displayed to perform the Teaching. It is recommended that you select a Priest with a high "Teach" attribute value as this will maximize the amount of Territory that you can gain through Teaching. Select "Teach" to confirm your selection, and the Priest will move to the target area and begin to spread your culture!