Desire without knowledge is not good, and whoever makes haste with his feet misses his way.
Proverbs 19:2 ESV

I think the TLV has the correct sense of this verse. Nephesh should be translated as zeal, not soul, flesh, or desire, although the latter isn't too far off.

"Fools rush in where angels fear to tread" as they say. It's good to act quickly when you know what you're doing and what the possible consequences are, but if you don't understand where you are or where you're headed, it's better to take the time to learn before acting.