The second class is composed of that large number of intelligent persons, in every community, who have not investigated this subject, who are willing to approach it in a spirit of candor and honest inquiry, anxious to accept anything which is reasonable and good, and equally intent upon rejecting that which is fraudulent and evil, and I invite the careful criticism of this class; and if, in my exposition of this subject, I announce a single proposition which will not bear the closest scrutiny; if I say aught which conflicts with common sense or reason, nay, if you can find one single natural fact to militate against the principles which I announce as fundamental to this science, I will be obliged to the gentleman or lady who will raise the question with me, and I will either prove my position to the satisfaction of this audience or retire from the field forever. [Illustration: Idiot.] The third class, unfortunately, are always with us, but I do not expect to convince them. They never were known to be convinced of anything. You can easily learn to distinguish an individual of this class by the shape of his head. Here is one I carry for illustration. He argues that the world is flat and does not revolve on its axis once in 24 hours, because, if it did, the water would all be spilled out of the Mississippi river. Life is too short to argue with this class, and I can only promise them that before I leave this platform they will be in the same category that a fellow was once who went to a prayer-meeting slightly intoxicated and fell asleep. Toward the close of the meeting everybody began to get happy, and the preacher called on everybody who wanted to go to Heaven to stand up. Everybody stood up but our intoxicated friend, who was awakened by the uprising. Then the preacher called on everybody who wanted to go to hell to stand up. Our friend by this time comprehended that something was before the house and staggered to his feet. He took one look at the preacher standing at the other end of the church and said: "Parson, (hic) I don't know what the question, is (hic) before the house, but you and I (hic) are in the smallest minority that ever I saw." So it is with you, my friends. If you don't believe in Phrenology when I dismiss you to-night, remember that you are in the minority in this audience, and a very small minority at that, composed of unprogressive mossbacks and persons of small mental capacity, and if you will call at my rooms to-morrow, I'll tell you to which of these classes you belong. In the study of scientific topics it is well in the outset to establish definitions. I will, therefore, commence by looking our subject squarely in the face, and establishing a concise definition of Phrenology.