There is but one God, says Pliny, and this God manifests Himself in Nature. Nature and Nature's work are one. This world and all other worlds we see or can think of are parts of Nature. If there are other Universes, they are natural; that is to say, a part of Nature. God rules them all according to laws which He Himself can not violate. It is vain to supplicate Him, and absurd to worship Him, for to do these things is to degrade Him with the thought that He is like us. The assumption that God is very much like us is not complimentary to God.
God can not do an unnatural or a supernatural thing. He can not kill Himself. He can not make the greater less than the less. He can not make twice ten anything else than twenty.
He can not make a stick that has but one end. He can not make the past, future. He can not make one who has lived never to have lived. He can not make the mortal, immortal; nor the immortal, mortal. He can change the form of things, but He can not abolish a thing. Pliny preaches the Unity of the Universe and his religion is the religion of Humanity.
Pliny says:
"We can not injure God, but we can injure man. And as man is part of Nature or God, the only way to serve God is to benefit man. If we love God, the way to reveal that love is in our conduct toward our fellows."
Pliny was close upon the Law of the Correlation of Forces, and he almost got a glimpse of the Law of Attraction or Gravitation. He sensed these things, but could not prove them. Pliny touched life at an immense number of points. What he saw, he knew, but when he took things on the word of Marco Polo and Sir John Mandeville (for these gentlemen adventurers have always lived), he fell into curious errors. For instance, he tells of horses in Africa that have wings, and when hard pressed, fly like birds; of ostriches that give milk, and of elephants that live on land or sea equally well; of mines where gold is found in solid masses and the natives dig into it for diamonds.
But outside of these little lapses, Pliny writes sanely and well. Book Two treats of the crust of the earth, of earthquakes, meteors, volcanoes (these had a strange fascination for him), islands and upheavals.
Books Three and Four relate of geography and give amusing information about the shape of the continents and the form of the earth. Then comes a book on man, his evolution and physical qualities, with a history of the races.
Next is a book on Zoology, with a resume of all that was written by Aristotle, and with many corroborations of Thompson-Seton and Rudyard Kipling. Facts from the "Jungle Book" are here recited at length. Book Nine is on marine life—sponges, shells and coral insects. Book Ten treats of birds, and carries the subject further than it had ever been taken before, even if it does at times contradict John Burroughs. Book Eleven is on insects, bugs and beetles, and tells, among other things, of bats that make fires in caves to keep themselves warm. Book Twelve is on trees, their varieties, height, age, growth, qualities and distribution. Book Thirteen treats of fruits, juices, gums, wax, saps and perfumes. Book Fourteen is on grapes and the making of wine, with a description of the process and the various kinds of wine, their effects on the human system, with a goodly temperance lesson backed up by incidents and examples.
Book Fifteen treats of pomegranates, apples, plums, peaches, figs and various other luscious fruits, and shows much intimate and valuable knowledge. And so the list runs down through, treating at great length of bees, fishes, woods, iron, lead, copper, gold, marble, fluids, gases, rivers, swamps, seas, and a thousand and one things that were familiar to this marvelous man. But of all subjects, Pliny shows a much greater love for botany than for anything else. Plants, flowers, vines, trees and mosses interest him always, and he breaks off other subjects to tell of some flower that he has just discovered.