Voltaire's Philosophical Dictionary

This book does not demand continuous reading; but at whatever place one opens it, one will find matter for reflection. The most useful books are those of which readers themselves compose half; they extend the thoughts of which the germ is presented to them; they correct what seems defective to them, and they fortify by their reflections what seems to them weak. It is only really by enlightened people that this book can be read; the ordinary man is not made for such knowledge; philosophy will never be his lot.
Those who say that there are truths which must be hidden from the people, need not be alarmed; the people do not read; they work six days of the week, and on the seventh go to the inn. In a word, philosophical works are made only for philosophers, and every honest man must try to be a philosopher, without pluming himself on being one. This alphabet is extracted from the most estimable works which are not commonly within the reach of the many; and if the author does not always mention the sources of his information, as being well enough known to the learned, he must not be suspected of wishing to take the credit for other people's work, because he himself preserves anonymity, according to this word of the Gospel: "Let not thy left hand know what thy right hand doeth."