God has given us one little thing, which you know nothing of.

He has given us the knowledge of certain medicines by which we can make rain.

WE do not despise those things which you possess, though we are ignorant of them.

We don't understand your book, yet we don't despise it.

YOU ought not to despise our little knowledge, though you are ignorant of it.
M.D.I don't despise what I am ignorant of; I only think you are mistaken in saying that you have medicines which can influence the rain at all.
R.D.That's just the way people speak when they talk on a subject of which they have no knowledge.