P3: An affect which is a passion ceases to be a passion as soon as we form a clear and distinct idea of it.

Dem.: An affect which is a passion is a confused idea (by Gen. Def. Aff.). Therefore, if we should form a clear and distinct idea of the affect itself, this idea will only be distinguished by reason from the affect itself, insofar as it is related only to the Mind (by IIP21 and P21 S). Therefore (by IIIP3), the affect will cease to be a passion, q.e.d.

Cor.: The more an affect is known to us, then, the more it is in our power, and the less the Mind is acted on by it.