We must find a way to treat these diseases by not allowing the defilements to arise. But how do we prevent the defilements from arising? First we must look on a broader scale. Just now we looked at things in terms of ourselves, seeing the disease as something that arises in our own minds, in our own lives. We saw defilements arising in our own minds, while conditions, which are impermanent and imperfect, we saw as ourselves. But if we look on a broader scale we will see clearly that the disease (roga) is based on contact with the world (loka).
The spiritual disease and the world are connected. What is the connection? Why do greed, hatred and delusion arise within us, how do these things come about? Generally speaking, defilements arise from contact with the world. The world makes contact with us and we make contact with the world. How do we make contact with the world? We do so through our everyday experience, in sense contact, from receiving sense impressions through the eye, ear, nose, tongue, body and mind. Sensations that arise through the eye are called sights; those entering through the ear are called sounds; those entering through the nose are called smells; those entering through the tongue are called tastes; those entering through the body are called tactile sensations; those entering through the mind are thoughts and feelings. We experience our selves through these sensations. Whenever we experience no sensations, such as when we are in deep sleep or unconscious, we are not aware. When we are aware it is through these sensations.
From where do these sensations arise? They come from the world, our environment. Our environment manifests itself to us through the eyes, ears, nose, tongue, body and mind, which in Buddhism we call the six sense bases. Any experience that appears to us must appear to us through these entrances, as sights, sounds, smells, tastes, bodily feelings and thoughts.
Now these sensations, or experiences, appear to us and there is contact, after which follows an immediate response. All these experiences can therefore be seen as bases for greed to arise, for hatred to arise or for delusion to arise. If we have no Dhamma medicine, we will fall under the power of sensations and the corresponding reactions will take place: when a sensation that is a base for greed arises, we want to possess it; if a sensation that is a base for hatred arises, instead of seducing us into desire, it upsets us and taunts us into anger. This is how defilements arise in response to sense impressions.
In the case of the ordinary, untrained person (puthujjana), whenever a sense impression arises there will initially follow a feeling of pleasure or displeasure, depending on whether the sensation is agreeable or not. If it is agreeable to us there is a feeling of pleasure and there follows a reaction of liking or approval. Seeing a pleasant sight, or hearing a pleasant sound, we feel approval. If it's a sight that offends our eyes or a sound that grates our ears, one that we perceive to be unpleasant, there is a reaction of disapproval.
From these initial reactions of approval and disapproval arise mental proliferations, thoughts about sense objects which become problems in our mind and cause it to become stained and dull. The disease arises. So this disease arises within the mind, it's true, but it comes as a result of experiencing sensations, or the world as it appears to us through our senses.