P9: If an affect is related to more and different causes which the Mind considers together with the affect itself, it is less harmful, we are less acted on by it, and we are affected less toward each cause, than is the case with another, equally great affect, which is related only to one cause, or to fewer causes.

Dem.: An affect is only evil, or harmful, insofar as it prevents the Mind from being able to think (by IVP26 and P27). And so that affect which determines the Mind to consider many objects together is less harmful than another, equally great affect which engages the Mind solely in considering one, or a few objects, so that it cannot think of others. This was the first point.

Next, because the Mind’s essence, i.e., power (by IIIP7), consists only in thought (by IIP11), the Mind is less acted on by an affect which determines it to consider many things together than by an equally great affect which keeps the Mind engaged solely in considering one or a few objects. This was the second point.

Finally (by IIIP48), insofar as this affect is related to many external causes, it is also less toward each one, q.e.d.