System of Knowledge and Explanation

"Organized knowledge of a subject and the interrelationship of its various parts, is superior to disorganized knowledge – just as a beautiful garden arranged with beds of flowers, paths and rows of plants is superior to a chaotically overgrown forest...A person should always endeavour to grasp general principles...When a person understands one principle he automatically understands a great number of details."

Introduction to R. Moshe Luzzatto (Ramchal) Derech HaShem.

Wesley Salmon (Four Decades of Scientific Explanation, 1990) argues a description of what "explanation" is:

[explanations] show how empirical phenomena fits into a causal nexus (paraphrase p.121)... the explanation of events consists in fitting them into the patterns that exist in the objective world. When we seek an explanation, it is because we have not discerned some feature of the regular patterns; we explain by providing information about these patterns that reveals how the explanandum-events fit in.... explanation reveal the mechanisms, causal or other, that produce the [events] we are trying to explain. (p 121).  

The challenge is when we're aware that we don't know adequately or completely the regular patterns, or mechanisms that produce the events, and we know that we never will know them completely.