How much must one practice to attain enlightenment?

It is a question that people who are new to Buddhism or who are curious to Buddhism sometimes ask. As with all my writings on such topics don't make more or less out of my answers than necessary (I cannot emphasize enough I am not ordained or recognized as any kind of dharma teacher). I would answer that I could practice constantly and sincerely in a single lifetime for a thousands years without realizing enlightenment.

Some might think I am suggesting it will take even longer, but really I am saying that enlightenment is not tied in a reliable, formulaic way to practice (either by quantity or quality). It isn't a stage of achievement or a rank of skill or knowledge. It involves understanding without preconception or judgement and acting in away that is guided by such understanding. I think sometimes people have the notion that a Buddha or Bodhisattva has transcended their humanity and no longer has any passion or feeling. Not so. Or some may think a realized Buddha (one who has perceived their Buddha-nature, i.e. someone who is enlightened) is immune to the conditions around her or himself which provoke delusions, greed, and passion. That is perhaps partially true, but it does not mean they do not know fear, or guilt, or anger. These along with other emotions and passions are a part of being human. How can one be enlightened, that is, truly see themselves as they are, by denying a fundamental aspect of their own existence?

One cannot purge the human body and mind of emotion or selfishness. One cannot live a life where they do not jump to conclusions, misjudge, or make similar mistakes. Buddhism cannot purify you by purging you of your basic human nature, though I get the distinct impression some people believe this to be so. So how does a realized Buddha manage to deal with this? By practicing compassion through wisdom and expanding their (metaphorical) heart. This follows the classic analogy that shows up time and again in Asian religious imagery (especially Buddhism)--that of a drop of ink. If you place a drop of ink in a glass of water, all the water will turn black. If you place a drop of ink in the ocean, it will simply vanish. If our hearts are small and limited to a selfish point of view, they will easily be overwhelemed when provocations come along. If our hearts are vast, then like a drop ink in the ocean, the provocations will be impotent. This analogy has been used over and over by popularizers of Buddhism in the English speaking world like His Holiness the Dalai Lama Tenzin Gyuatso or Thich Nat Hahn, but perhaps this is not seen in terms of enlightenment or being a realized Buddha.

That is, a Buddha's patience (ksanti) comes from the spaciousness of his heart, not from a lack of provocation or temptation. I think it is important to realize that the analogy is not about avoiding the drop of ink or making a lid for the glass, yet sometimes it sounds to me like this is what some (Buddhist) practioners are hoping to accomplish. Of course it is true that we can and should act to limit exposure to unnecessary provocation, and following the various precepts and basic vows can help us with that. But though we might strive a thousand years to discipline our thoughts, speech, and action, if we do not see the world as it is and use that wisdom to open ourselves to that ocean of compassion, we will not have realized enlightenment.