Full Idea
Knowledge 'that' is descriptive, and knowledge 'why' is explanatory, and it is the latter that provides scientific understanding of our world.
Gist of Idea
It is knowing 'why' that gives scientific understanding, not knowing 'that'
Source
Wesley Salmon (Four Decades of Scientific Explanation [1989], Intro)
Book Reference
Salmon,Wesley C.: 'Four Decades of Scientific Explanation', ed/tr. Humphreys,Paul [Pittsburgh 2006], p.3
A Reaction
I agree, but of course, knowing 'why' may require a lot of knowing 'that'. People with extensive knowledge 'that' things are so tend to understand why something happens more readily than the rest of us ignoramuses.