An immense debt of acknowledgement goes to all those persons, thriving within the shelves of my library, that with their stimulating thoughts and suggestions, contributed to this work. Most of them are mentioned in the bibliographical notes. As for those who are not mentioned, all of them invaluable in adding to my small store of knowledge, they are hidden in the far recesses of memory. This is their book, started millennia ago, to which little I might have succeeded in adding save for what my mind, picking pearls here and there in this vast literature, dwelled upon contributing, perhaps, some original and stimulating thoughts.

For any inconsistencies, errors, or absurdities that you may find in this work I am solely responsible, although I have a good anecdote as an excuse: at my birth, my mother had little if any milk since the English troops had already captured my hometown, which was locked in curfew; hence little if anything was available to feed me. A young Eritrean man at our service, whose name, Elias Uoldegabriel, deserves to be remembered, notwithstanding the curfew, somehow daily managed to procure some she-donkey milk which, mixed with a good dose of water and perhaps a little sugar allowed me to survive. That's how from there I got here...