[bluGill]

They can be, but you need to take care as sometimes they are misleading and can even drive wrong decisions.

[fhdkweig]

Aesop wrote a lot of fables that had contradictory lessons.

[bluGill]

I have more than once in life realized that one of the two contradictory lessons was correct for this situation, but in a different one the other was correct...

[HPsquared]

There's a meta-lesson there.