Forgotten Thinkers

Who are some philosophers or people with philosophical ideas you think are largely unknown, forgotten, or underrated? Personally I’d go with guys like the anarchist nihilist Renzo Novatore, Max Stirner (though he’s popular on edgy Internet forums), the pessimist Phillip Mäinlander, and the panpsychist physicist Gustav Fechner (who actually has a pretty inspiring biography). If you’ve heard of the philosophers on my list what do you think of them?