Rationalist philosopher dude who lived a long time ago.
He basically said that substance is god, or nature, and that every existing thing is one. That kinda made Christian Europe mad and they actually started using the word "Spinozist" as almost a swear word for "atheist".
Then there was this huge intellectual controversy when
Jacobi and Mendelssohn were both
writing a book about
Lessing, who had just died, and they started exchanging letters about it and things got kinda heated when Jacobi took things a little too seriously and competed to have his book printed first. Mendelssohn didn't get as aggresive as Jacobi, but the poor dude ended up dead when he caught a cold trying to send in his
manuscript.
Anyway, the reason why this caused so much controversy was because Jacobi claimed that Lessing admitted to being a spinozist and Mendelssohn was friends with Lessing so everyone was like omg no way cause Mendelssohn was a leader of the Berlin Enlightenment and the starter of modern Judaism and being called an atheist or
pantheist wasn't exactly a good thing back then.
Long story short,
Jacobi's book got printed, in which he actually criticized
Spinoza saying that yeah, Spinoza may be right in his ideas but reason leads to atheism and denial of free will so we should have faith. Or something like that. Bu interestingly enough, this criticism restarted an interest in Spinoza. And here we are today, still talking about the dude.
Example:
"What's up?"
"Oh not much. Just writing a paper on
Jacobi and
Spinoza for my philosophy class."
"Wait, why are you even taking philosophy?"
"So I can show off my
mad knowledge on random websites."