Site meter showed that this blog got a hit from the search query, "how to reason with a 3 year old." I must say that really made me laugh. Came to the wrong place for that answer! ha, ha, ha!!!
How do you reason with a three year old? You don't. You just have to patiently teach them, be truthful, be lovingly firm (i.e. you don't give in to their every whim and demand and temper tantrum), you certainly don't argue with their circular reasoning, and be very, very consistent. Be the mom!