P6: Insofar as the Mind understands all things as necessary, it has a greater power over the affects, or is less acted on by them.

Dem.: The Mind understands all things to be necessary (by IP29), and to be determined by an infinite connection of causes to exist and produce effects (by IP28). And so (by P5) to that extent {the mind} brings it about that it is less acted on by the affects springing from these things, and (by IIIP48) is less affected toward them, q.e.d.

Schol.: The more this knowledge that things are necessary is concerned with singular things, which we imagine more distinctly and vividly, the greater is this power of the Mind over the affects, as experience itself also testifies. For we see that Sadness over some good which has perished is lessened as soon as the man who has lost it realizes that this good could not, in any way, have been kept. Similarly, we see that no one pities infants because of their inability to speak, to walk, or to reason, or because they live so many years, as it were, unconscious of themselves. But if most people were born grown up, and only one or two were born infants, then everyone would pity the infants, because they would regard infancy itself, not as a natural and necessary thing, but as a vice of nature, or a sin. We could point out many other things along this line.