Jason wrote:Belton wrote:As such "Japanese For Busy People" doesn't use へ only に。
This is a different class of に. This is not a "motion towards" に, but a "for the purpose/sake of" に. に has all sorts of different uses.
I know of the myriad uses of に. (I'm starting to think when in doubt use に, the odds are in your favour.

)
for motion verbs JFBP briefly introduces へ and then explicitly uses に in all cases where either can be used.
It does point out the usage difference as
へ expresses direction
に expresses arrival at a destination
As I said I'd look it up.
from Naoko Chino's
All About Particles
へ
1. Indicates a direction or goal, or a destination toward which one is moving or at which one has arrived:"to"
(seems to contradict JFBF

)
2. Indicates a recipient of an action (in English, equivalent to the indirect object): "to"
In both usages に may replace へ except when へ is followed by の in usage 2.
に
(amongst 15 different uses are)
• Indicates movement from a larger to a smaller place. (both physical and abstract):"in, into"
(contrast with を-- movement from a smaller to a larger place)
• Indicates movement toward a place: "to"
(へ may also be used here)
(and similar to へ #2 above)
• Indicates the recipient of an action (in English, equivalent to the indirect object): "to, from".
When the meaning is "to" へ may replace に. When the meaning is "from" から may replace に