The next temperaments that Locke explores are cowardice and courage. Fear is a useful emotion, since it helps keep us on guard for danger. Excessive fear and excessive lack of fear, though, are both bad. If a child seems to lack fear the best way to deal with the problem is to awaken his reason. Once the dangers of his actions are vividly laid out for him, his sense of self-preservation will kick in and force him to adhere to reason. A much more common inclination, though, is cowardice. This is a particularly bad inclination because without courage a man cannot perform his other duties. Courage is the ability to perform one's duties no matter what danger lies in one's way. True courage must persist in the face not only of death, but also of pain, disgrace, and poverty.
Locke has a three-part plan for combating cowardice in children. First, they should never be told scary stories because this unsettles their spirit. Secondly, they should carefully be made accustomed to anything that frightens them. People are only afraid of what can pain them, and so once a child sees that the object of their fears will cause them no pain, they will cease to be afraid. Finally, in a loving and playful context, children should be exposed to some mild pain, such as gentle punching or pinching. After withstanding the gentle pain they should be praised for their courage and manliness. They will thus come to prefer having a reputation for bravery over avoiding a little pain.
The next temperament that Locke turns to is cruelty. Children have a tendency, he points out, to torture small animals. This sort of pleasure should be eliminated as soon as possible, because it will lead to cruelty and oppression of human beings later in life. Instead, the parents must instill a horror of killing or hurting any living creature, and of destroying any living thing. Locke is certain that the desire to kill or torment is actually unnatural to any human being. Children learn it through the culture, in particular through entertainment and history, both of which view conquerors as heroes.
Another important way in which to ensure that the child grows up with humane sentiments is to have them treat the servants decently. Poor treatment of servants will encourage pride and contempt for those beneath them and this too will end in oppression and cruelty.
Locke next moves on to a positive inclination, curiosity. Curiosity is an appetite for knowledge, the great instrument that nature provided us with in order to remove our ignorance. It should be encouraged as much as possible. In fact, Locke goes so far as to say, children who do not like knowledge generally feel this way because their natural curiosity was discouraged rather than encouraged. The way to encourage curiosity is to always answer a child's questions in the most direct and easily intelligible way; to never laugh at a question; to tell other people about the child's new knowledge in front of the child so that he becomes proud (the most effective means, Locke suggests, is to have the child teach his new knowledge to younger siblings); and, finally, to never give deceitful or elusive answers. If a child asks a question which stumbles on forbidden territory, it is better to tell the child that he is not allowed to know the answer than to make up a false answer. Children can tell when they have been given a false answer, and so not only will misleading them thwart their quest for knowledge, it will also teach them the vice of lying.
Locke, as we see in this section, does not believe in the possibility of pure cruelty, or hatred for its own sake. He thinks that no one is born liking to kill or hurt or destroy. Instead, people are unnaturally reconciled to this sort of behavior because it is valorized in our culture. People think that these inclinations are heroic and so they overcome their inherent aversion.
There are two questions we can ask about this claim: First, just because there is no naturally occurring cruelty, does that mean that cruelty cannot be a source of evil in the world? Second, is Locke really justified in claiming that there is no naturally occurring cruelty?
As for the first question, the answer clearly seems to be "no". Regardless of whether cruelty is a quality that people are naturally born with, Locke himself admits that it is a quality that many people acquire. So long as people have this quality, it can be responsible for evil in the world. But is it? Locke still might have a case, if he only weakens his claim a little. Cruelty, when we get right down to it, is rarely the only motivation in an act. Usually cruel people choose their cruel actions based on a desire for power or money or some other lust that would fall under the general heading of "dominion". Locke might be able to say, then, that dominion is the source for almost all injustice and contention in the world, with pure cruelty (and maybe a few other sentiments, such as ideology) accounting for another small percentage.
Locke's contention that no one is born with a desire to kill, hurt, or destroy is the first instance of his tendency to underestimate the nature side of the nature-nurture debate. As we will see again and again, Locke does not really seem to take seriously the possibility of a full human diversity of temperaments. The discussion on curiosity is another such instance. There, Locke claims that most children who do not like knowledge do not like knowledge because their curiosity was stifled. Perhaps, though, these children do not like knowledge because they were simply born without a strong intellectual proclivity. Perhaps they never really had an intellectual curiosity to begin with. Locke does not consider this possibility, even though he claims to give much weight to the natural temperament of a child. Again, Locke might be right to claim that every child is born with an intellectual curiosity, but he has no evidence to back up this claim. Like the claim about natural cruelty, the claim about natural curiosity can only be settled through empirical investigation.