QUESTION: From the three poisons, I understand the concepts of greed and hate very well, but find delusion or ignorance more difficult to make sense of. Could you say something about it?
SHORT ANSWER: Delusion is pride.
LONGER ANSWER: Delusion is the distortion of perception and thinking brought about by the "conceit of self" - attachment to the ideas we have of ourselves and particularly the tendency to regard oneself as a special case. it could be in a "positive" or "negative" fashion. By this I mean that we might have ideas of grandiosity or of self-pity. Self-power is basically a form of grandiosity. Playing the victim is self-pity. Delusion can also be multiplied up by the capacity that humans have for deception, including self-deception. Hence false humility. What presents as "guilt" may, for instance, have at its root an inflated sense of self. The person does not really regret the harm they did, they just hate the experience of perceiving evidence that they are not what they would like to think that they are.
Greed and hate can be thought of as existing at two levels. There is a basic attraction-repulsion level that is largely instinctive - as in that one likes some tastes and dislikes others. But then there is the more complex case where the attraction-repulsion is itself grounded in delusion. At this level we love what supports our self-attachment and we hate what threatens it. Many of our more complex emotions are triggered in this way - resentment, jealousy, envy, spite, possessiveness, vengeance and so on.
The three poisons also get displaced into various specific pathologies. A fairly clear example is eating disorders. Compulsive eating is clearly a greed condition, but it also serves a number of self-building functions making the person bigger so that they carry more weight while at the same time making them less sexually attractive thus avoiding what may be an area of difficulty. Anorexia is just as clearly a hate condition, but again it serves complex self-building and inter-personal functions manipulating and punishing others as well as self. Bulimia is more directly in the province of delusion, being a love-hate activity in which the person is at war with him/herself. All these conditions include dimensions of refusal to really accept what it is to be an incarnate being living in a material world.
Delusion is conceit. It is what brings spiritual danger and leads us astray. In simple terms, this is pride. It may be clearly manifest or it may be hidden under all kinds of social strategies and dissimulation, but it is the root cause of our troubles.