Full Idea
If the universe is more like animal bodies and vegetables than works of human art, it is more probable that its cause resembles the cause of the former than of the latter, and its cause should be ascribed to generation rather than to reason of design.
Gist of Idea
Creation is more like vegetation than human art, so it won't come from reason
Source
David Hume (Dialogues Concerning Natural Religion [1751], Part 7)
Book Reference
Hume,David: 'Dialogues Concerning Natural Religion' [Penguin], p.86