Full Idea
Two things fill the mind with ever new and increasing wonder and awe, the oftener and the more steadily we reflect on them: the starry heavens above me and the moral law within me.
Gist of Idea
What fills me with awe are the starry heavens above me and the moral law within me
Source
Immanuel Kant (Critique of Practical Reason [1788], Concl)
Book Reference
Kant,Immanuel: 'Critique of Practical Reason (Third edition)', ed/tr. Beck,Lewis White [Library of Liberal Arts 1993], p.169
A Reaction
I am beginning to think that the two major issues of all philosophy are ontology and metaethics, and Kant is close to agreeing with me. He certainly wasn't implying that astronomy was a key aspect of philosophy.