CHAPTER XXI. THE PROFESSOR’S LECTURE. “In Science—in fact, in most things—it is usually best _to begin at the beginning_. In _some_ things, of course, it’s better to begin at the _other_ end. For instance, if you wanted to paint a dog green, it _might_ be best to begin with the _tail_, as it doesn’t bite at _that_ end. And so——” “May _I_ help oo?” Bruno interrupted. “Help me to do _what_?” said the puzzled Professor, looking up for a moment, but keeping his finger on the book he was reading from, so as not to lose his place. “To paint a dog green!” cried Bruno. “_Oo_ can begin wiz its _mouf_, and I’ll——” “No, no!” said the Professor. “We haven’t got to the _Experiments_ yet. And so,” returning to his note-book, “I’ll give you the Axioms of Science. After that I shall exhibit some Specimens. Then I shall explain a Process or two. And I shall conclude with a few Experiments. An _Axiom_, you know, is a thing that you accept without contradiction. For instance, if I were to say ‘Here we are!’, that would be accepted without any contradiction, and it’s a nice sort of remark to _begin_ a conversation with. So it would be an _Axiom_. Or again, supposing I were to say ‘Here we are not!’ _that_ would be——” “—a fib!” cried Bruno. “Oh, _Bruno_!” said Sylvie in a warning whisper. “Of course it would be an _Axiom_, if the Professor said it!” “—that would be accepted, if people were civil,” continued the Professor; “so it would be _another_ Axiom.” “It _might_ be an Axledum,” Bruno said: “but it wouldn’t be _true_!” “Ignorance of Axioms,” the Lecturer continued, “is a great drawback in life. It wastes so much time to have to say them over and over again. For instance, take the Axiom ‘_Nothing is greater than itself_’; that is, ‘_Nothing can contain itself_.’ How often you hear people say ‘He was so excited, he was quite unable to contain himself,’ Why, _of course_ he was unable! The _excitement_ had nothing to do with it!” “I say, look here, you know!” said the Emperor, who was getting a little restless. “How many Axioms are you going to give us? At _this_ rate, we sha’n’t get to the _Experiments_ till to-morrow-week!” “Oh, sooner than _that_, I assure you!” the Professor replied, looking up in alarm. “There are only,” (he referred to his notes again) “only _two_ more, that are really _necessary_.” “Read ’em out, and get on to the _Specimens_,” grumbled the Emperor.