Kant Immanuel's work should also be listed, at least within the top 20s. It has resulted in creating the base of liberalism in Europe, and ideas of the useless United Nation.
Kant wasn't 19th or 20th century. Besides, I think Rousseau (not the right period either) was the more responsible for modern European (so-called) liberalism.
You are right about Kant except that his Critique of Pure Reason was published in the 18th century, 1781 to be exact.
You inverted Immanuel Kant's name. Here's a little ditty to remind you of his name and those of other philosophers:
Immanuel Kant was a real pissant
Who was very rarely stable
Heidegger, Heidegger was a boozy beggar
Who could think you under the table
David Hume could out-consume
Schopenhauer and Hegel
And Wittgenstein was a beery swine
Who was just as sloshed as Schlegel
There's nothing Nietszche couldn't teach ya
'Bout the raising of the wrist
Socrates himself was permanently pissed
John Stuart Mill of his own free will
On half a pint of shandy was particularly ill
Plato they say could stick it away
Half a crate of whiskey every day
Aristotle, Aristotle was a bugger for the bottle
Hobbes was fond of his Dram
And Rene Descartes was a drunken fart
"I drink, therefore I am !"
Yes Socrates himself is particularly missed
A lovely little thinker
But a bugger when he's pissed.
You greatly misunderstand Kant...
He is probably the last philosopher who attempted (and succeeded) in reconciling metaphysics (aka God) and reason.
Hence "Critique of pure reason". His work was so good (like Aquinas), that nobody topped it. Heck, nobody bothered.
Instead philosophers either accepted it or just rejected metaphysics (the positivists).
It was the *rationalists* - Descartes, then Rousseau - who were the forebears of European rationalist ideology, that created the French revolution 'idees' and socialism and the ills that fell from that.