Introduction to the theory and application of differential equations with deviating arguments Book

Every few years I take this book out and reread it. Yolen writes with deceptive simplicity and clarity that one doesn't realize how profoundly true her words are until they keep coming back in memory.

From this book comes a (deservedly) repeated quotation, which I reproduce here, as I use it frequently to give the short answer why I can't read game of Thrones, well-written as it is:

And for adults, the world of fantasy books returns to us the great words of power which, in order to be tamed, we have excised from our adult vocabularies. These words are the pornography of innocence, words which adults no longer use with other adults, and so we laugh at them and consign them to the nursery, fear masking as cynicism. These are the words that were forged in the earth, air, fire, and water of human existence, and the words are:

Love. Hate. Good. Evil. Courage. Honor. Truth."

And:

"Touch magic. Pass it on."