僕はもっとずっと後に、科学哲学を勉強していたとき、実験というのは既存の知識に対する現実の不満から生じるべきものだということを学んだ。

、、。

Much later, when I was studying philosophy of science, I learned that experiments should arise from real dissatisfaction with existing knowledge.

Literal

I [topic-は] much-more later [at-に], science-philosophy [object-を] was-studying [when-とき], experiment [quotative-という] [nominalizer-の] [topic-は] existing knowledge [toward-に対する] reality [possessive-の] dissatisfaction [from-から] should-arise thing [quotative-だということ] [object-を] learned.

An exceptionally dense sentence. Key structures: ~ていたとき ('when I was studying'), ~というのは ('as for what's called X'), に対する ('toward, regarding'), ~べきもの ('something that should'), ~ということを学んだ ('learned that'). 科学哲学 ('philosophy of science'). 既存 (きそん, 'existing'). Multiple layers of embedding make this N1-level material.