“Each thing, as far as it can by its own power, strives to persevere in its being.”Baruch Spinoza · Etica · 1677 · Partea a III-a, propoziția 6
To exist is to strive to remain: perseverance is not a chosen goal, but the very structure of being.
For Spinoza, to exist means to have a power that maintains itself; if the power fades, the thing fades too. So perseverance is not a chosen goal but the very structure of being. A plant turns its leaves toward light without deciding to; a person defends health, name and bonds out of the same reflex of existence.
If perseverance is the structure of being, then emotions get a simple explanation. Spinoza sees them as changes in your power to exist. Something increases your power, you feel joy. Something decreases it, you feel sadness. This is not about morality, but about the mechanics of existence. An example: after a conversation where someone truly listens to you, you feel more alive. After one where you are humiliated, you feel diminished. These are not opinions, but signals about the state of your power. From here comes a practical question: which people and which habits increase your power, and which quietly drain it? The next step shows why you cannot simply choose to feel otherwise.
Why it matters It gives you an honest measure: something is good for you if it increases your power to live, not if it merely looks good on paper.