Instruction has two useful effects: first, it increases the resources of a man, renders him better qualified for a greater variety of things; it is then, as political economy styles it, a capital. Parents, in having their children taught, give them thereby a far more substantial and productive capital than what they could transmit to them by gift or legacy. In the second place, instruction elevates man and ennobles his nature. If it is reason that distinguishes man from the brute, knowledge enlarges and heightens reason. Instruction thus works together with moral education and forms one of its essential parts. The head of a family who then, from personal interest, negligence, ill-will, or, in fine, from ignorance, deprives his children of the instruction which is their due, fails thereby in an essential duty.[79] It must, moreover, be admitted, that instruction alone does not suffice; science alone does not form character; persuasion, authority, example, the moral action of every instant is necessary thereto. It is a great problem to know how much of fear and gentleness, restraint and liberty should enter in paternal education. All agree that a child should not be brought up through fear alone, as the animals are. As Fénélon admirably puts it, "Joy and confidence should be the natural state of mind of children; otherwise their intelligence becomes obscured, their courage droops; if they are lively, fear will irritate them; if soft, it will make them stupid; fear is like the violent remedies employed in extreme illnesses: they purge; but they injure the constitution and wear out its organs; a soul led by fear is always the feebler for it." On the other hand, everybody admits also that an excessive indulgence is as dangerous as a despotic authority. Rousseau ingenuously remarks: "The best means of making your child miserable is to accustom it to obtaining all it wants; for its desires will incessantly grow with the facility with which it can satisfy them; sooner or later the inability to content it, will, despite yourself, oblige you to refuse, and this unexpected denial will give it more pain than the deprivation of the thing itself. First it will want the cane you have in your hand; then your watch; then the bird in the air; the bright star in the sky; in short, all that it sees: and unless you were a god, how could you satisfy it?" This remark of Rousseau refers to the earliest childhood, but it can be applied to all ages.