“Luminous, monks, is the mind. And it is defiled by incoming defilements.”[i]
According to Early Buddhism, the nature of the mind, at the deepest level, is naturally pure and ‘brightly shining’. This latent, dynamic, ground-state continuum consciousness, imbued with loving-kindness and wisdom, called the bhavanga–citta in Pali, flows on like a smooth flowing river.
During waking moments, there is very rapid alternation between this pure unconscious mind and the conscious states that perceive sensory and mental objects. When we react to objects without clear comprehension it gives rise to craving and aversion, forming the ‘defilements’ that obscure the pure mind.
Obscurations of the mind distort the true perception of things, just as wearing tinted glasses would change the colors of the surroundings. They arise from our dualistic tendencies toward the objects we sensed. That is, we tend to judge things as good or bad, desirable or undesirable. The more we do this, the more defilement we add onto the pure mind. And the more the defilements, the less the wisdom, and thus more associated suffering. Since defilements arise from unwholesome roots, they can only yield unwholesome fruits.
However, although the defilements stain the pure mind, they cannot change its inherently pure nature. The defilements are adventitious unwholesome accretions arrived from the roots of delusion, greed and aversion, and they are not inherent with the ‘pure’ mind. They have been there for a long time, but they need not be there permanently. They are like guests that out-stayed their welcome and think that they are the masters of the house.
Thus, under all the defilements and obscurations lies the stainless and intrinsically radiant mind that has potential for enlightenment. This concept became known as the Buddha-nature.
Ajahn Chah said:
“In truth there is nothing really wrong with it. It is intrinsically pure. Within itself it’s already peaceful. That the mind is not peaceful these days is because it follows moods. The real mind doesn’t have anything to it; it is simply (an aspect of) Nature. It becomes peaceful or agitated because moods deceive it. The untrained mind is stupid. Sense impressions come and trick it into happiness, suffering, gladness and sorrow, but the mind’s true nature is none of those things. That gladness or sadness is not the mind, but only a mood coming to deceive us. The untrained mind gets lost and follows these things, it forgets itself. Then we think that it is we who are upset or at ease or whatever.
But really this mind of ours is already unmoving and peaceful… really peaceful! Just like a leaf, which is still as long as no wind blows. If a wind comes up the leaf flutters. The fluttering is due to the wind — the “fluttering” is due to those sense impressions; the mind follows them. If it doesn’t follow them, it doesn’t “flutter.” If we know fully the true nature of sense impressions, we will be unmoved.
“Our practice is simply to see the Original Mind. So we must train the mind to know those sense impressions, and not get lost in them. To make it peaceful. Just this is the aim of all this difficult practice we put ourselves through.”[ii]
That the radiant mind could be seen as Buddha-nature inherent in all beings expresses a very positive view and forms a basis for development and realization.
This is the reason why Buddhism has respect for all forms of life, as even the smallest sentient being has Buddha-nature and is capable of attaining enlightenment. For the same reason, Buddhism does not condemn anyone as inherently evil, as even though a person might have committed atrocious deeds and had a very defiled mind. However, at the deepest level his or her mind is still intrinsically pure and has the capacity to reveal its brightly shining nature by removing the defilements – through mental cultivation.
This was famously illustrated in the story of how the Buddha converted a
feared serial killer, Angulimala, into an enlightened saint – by showing him
the way to cultivate his mind through meditation.[iii]
[iii] MN 86. Angulimala Sutta: About Angulimala. Translated from the Pali by Thanissaro Bhikkhu. https://www.accesstoinsight.org/tipitaka/mn/mn.086.than.html