There are three roots to all unwholesome thoughts, and three roots to all wholesome thoughts. The three roots to all unwholesome thoughts are greed, hatred, and delusion. The three roots to all wholesome thoughts are non-greed, non-hatred, and non-delusion.
Greed is not only an uncontrollable desire for money. Greed can be a craving for more of anything: food; sensual pleasure; material possessions. It is never being satisfied with what we have, always wanting more. We are having dinner, and we over-eat, or are thinking about our next meal, never being content with what we have. Contentment is essential in mental development. Without it, we can never sit still or dwell in solitude.
Hatred is an aversion to anything we do not like. It can be quite gross, or very subtle. The grossest manifestation of hatred is seen when we get angry. Most often, it is so subtle, it isn't even recognized as hatred. Even our slightest dislikes fall under this category. When we realize how many dislikes we have, we realize how much hatred we harbor.
Delusion is the inability to see phenomena in its true nature. The mind is shrouded in ignorance, rendering it incapable of differentiating between reality and perception or what is imagined.
Greed and hatred cannot arise in the same thought, because one is wanting and the other is rejection. Greed and hatred are always accompanied by delusion.
Come, learn the roots of what disturbs the peace of mind... See how to recognize the underlying unwholesome tendencies, and begin to eradicate them...