Help me solve a problem: Active and Passive

[rainshine87]

Okay, I've got a rather pitiful knowledge of science, but I'm trying to solve a philosophical problem I've come upon, and I want to make sure I solve it in a manner that makes sense, so if any of you science buffs could help me out, I'd be grateful.
So imagine we've got two objects, object A and object B. Object A is active and object B is passive. Object A acts on object B, does object B then react? I've been looking into Newton's third law of motion which seems to indicate that this is the case. Perhaps someone could explain it to me simply.
All I'm really trying to figure out is how Object A, which is active, could become passive at the same time, and the same with object B - how it could become active whilst still being passive. I'm looking to see how a harmony could be born between the two where both take on an active and passive role.
If this is gobbledegook, please forgive me. Do explain to me where I'm going wrong if it is so.

[murex]

It reacts.

[MagnetMan]

I am inclined to metaphysics, and only marginally into physics.
Does this help:
If I put the right amount of reverse spin on a billiard ball and shoot it onto a stationary ball, the passive ball becomes active and the active ball becomes passive.

[atman]

What MM said. ..

Also the 'balance' idea and passive and active, harmony. I'm not that scientific, but seems those are attributtes in fluid dynamics.

Flows...

Waves...