ศีลคือความเป็นปกติของธรรมชาติแต่ละฝ่าย ส่วนข้อบัญญัติแห่งศีล 5 หรือศีล 8 เป็นกฎเกณฑ์ที่คุ้มครองเราไม่ให้อกุศลเข้าสิงจิตได้ หัวใจสำคัญของการรักษาศีลคือความบริสุทธิ์ในแต่ละข้อ ไม่ใช่เพียงสักแต่ว่าสมาทาน เพราะดวงศีลที่บริสุทธิ์จะเหนี่ยวนำกระแสธารแห่งบุญเข้ามาอย่างต่อเนื่องIn one sense, sila is simply the natural pattern of each of the three natures. But the precepts of the five or eight rules are guidelines that protect us from being possessed by the unwholesome. What matters most in keeping them is purity in each and every rule, not merely undertaking them as a formality — a truly pure precept draws in the stream of merit continuously.
Someone said they did not fully understand , and sometimes could not be sure whether what they had done was a mistake or was correct, and asked the teacher to explain.
Sila as the natural pattern of each nature
In one sense, sila means the natural pattern belonging to each of the three natures. The unwholesome's natural pattern is thinking, speaking, and acting in ways that destroy oneself and others — called "unwholesome sila." The neutral's natural pattern is taking neither good nor bad, absorbed in pleasure or in work without engaging in anything wholesome — called "neutral sila." The wholesome's natural pattern is doing good, helping others, speaking pleasantly and beneficially — called "wholesome sila." Every person carries a mixture of all three natures according to what they have accumulated, and their behavior and speech reflect that particular proportion.
The precepts as rules for safety
In another sense, sila refers to prohibitions or regulations — much like the rules of a hospital, a school, or the laws of a nation. The five and eight precepts are rules that protect us from falling into wrongdoing or causing harm to society. When we set the intention not to cause harm to others and hold to the precepts as our standard, the sphere of precepts within us brightens and draws in pure energy continuously, clearing away defilement and lifting us into progressively subtler inner dimensions — for as long as the precepts remain unbroken.
What matters most is purity, not merely undertaking them
Some people undertake the precepts without real attention, so a mixture of unwholesome or neutral patterns still remains — defeating the very purpose of undertaking them. What matters most is regularly examining each precept, one by one, to see whether it remains pure and complete. Every time the precepts are undertaken with genuine intention, the sphere of precepts brightens and draws in the stream of merit to cleanse defilement — as in the Buddha's saying: sīlena sugatiṃ yanti, precepts lead to a good destination; sīlena bhogasampadā, precepts bring wealth; sīlena nibbutiṃ yanti, precepts lead to Nibbana — because every kind of asset lies fully present within the field of merit that flows in together with the sphere of precepts.
How the five precepts differ from the eight
The five precepts guard against ; the eight precepts guard against both the unwholesome and the neutral, which is why additional rules are added — celibate conduct, not eating after midday, not adorning the body or watching entertainment — all meant to prevent the neutral nature from luring us into idle pleasure that wastes precious time. Precepts thus serve as the foundation for concentration, since they wear down the proportion of the unwholesome, making it easier for the mind to settle and become still. Someone with a large proportion of the unwholesome will feel uncomfortable when keeping precepts, because the unwholesome, as host of the heart, feels ill at ease — while a genuinely good person keeping precepts feels a sense of lightness and freedom, because the stream of merit flows through comfortably.