Fundamental to Spinoza’s philosophy is the idea of substance as “that which is conceived through itself.” But it’s hard for me understand the content of this phrase. What does it mean, for something to be conceived through itself? I feel like any example of a “conceiving through” that I can wrap my head around is of something that may be conceived through another thing, not a thing conceived through itself. This makes me wonder if the idea of that which is conceived through itself is a cognitively empty notion. What would Spinoza/Spinozists make of this reaction? I’m sure they would insist that, no, the idea of substance is not cognitively empty - but what, then, is its content?

Fundamental to Spinoza’s philosophy is the idea of substance as “that which is conceived through itself.” 

But it’s hard for me understand the content of this phrase. What does it mean, for something to be conceived through itself? I feel like any example of a “conceiving through” that I can wrap my head around is of something that may be conceived through another thing, not a thing conceived through itself. This makes me wonder if the idea of that which is conceived through itself is a cognitively empty notion. 

What would Spinoza/Spinozists make of this reaction? I’m sure they would insist that, no, the idea of substance is not cognitively empty - but what, then, is its content?