He felt keenly conscious of how barren all intellectual speculation is when separated from action and experiment.

他敏锐地意识到，如果脱离了行动和实验，所有的智力思考都是多么贫乏。

Athenians were taught a kind of reverence for the gods which consisted in outward observances and placed no barrier in the way of free intellectual speculation.

雅典人被教导对神明的一种敬畏，这种敬畏表现在外在的仪式上，并且不妨碍自由的思想思考。