To refrain from killing any living being.
To refrain from stealing.
To refrain from sexual misconduct.
To make a living that does not cause harm to oneself or others.
Needs to be tuned so it is neither too tight, nor too loose. I.e. don't burn yourself out, but also don't get lazy.
The four right efforts are:
1. prevention of unwholesome states of mind from arising. (By avoiding unwise attention to the fault; and unwise attention to the beautiful.)
2. abandonment of unwholesome states of mind should they arise.
3. generating wholesome states of mind.
4. sustaining those wholesome states of mind.
Unwholesome states of mind are the five hindrances: greed, aversion, sloth, restlessness, doubt.
Wholesome states of mind are the seven factors of enlightenment: mindfulness, investigation of phenomena (dhamma), energy (effort), joy, calmness, samhadi, equanimity (balance).
This is the four foundations of mindfulness.
Mindfulness of the body.
Mindfulness of feelings. (pleasant, neutral, or unpleasant).
Mindfulness of mental states.
Mindfulness of dhammas (teachings).
Sometimes translated as concentration, but concentration can give me the wrong idea, so I prefer to use the word samhadi. Samhadi is the gathering of the mind together into absorption, a unification of mind. Sustained mindfulness to a meditation object leads naturally to samhadi. It is a whole-hearted experience, which includes the body. The body can feel very pleasant and comfortable in samhadi. There may still be aches and pains in the physical body, but these don't bother one. One is absorbed in the experience of the body as it feels from within, the subtle body.
Emotions such as joy can be a whole body experience.
The body is in the mind.
A meditation object is used to calm and centre the mind, gather it together and bring it into unity and balance. Common meditation objects used are the breath, natural elements, primary colours, perception of light, or the emotion of goodwill (metta).
The Buddha classifies right samhadi as the four jhanas.
Here are some verses from the suttas that describe the four jhanas.
'Having gone somewhere quiet, away from distractions. Having removed longing and dejection in regard to the world, setting mindfulness before one.
Quite secluded from sense-pleasures and unwholesome states of mind. One enters and abides in the first jhana. Which is accompanied by applied and sustained thought (or attention). And has the joy and pleasure born of seclusion (from unwholesome states).
With the subsiding of applied and sustained thought. One enters and abides in the second jhana. Which is accompanied by self-confidence and unification of mind. Is without applied and sustained thought, and has the joy and pleasure born of samhadi.
With the fading away of joy. One abides in equanimity. And mindful, clearly comprehending, still feeling pleasure with the body. One enters and abides in the third jhana. On account of which the noble ones say: 'one has a pleasant abiding, who has equanimity and is mindful.'
With the fading away of pain and pleasure. And the previous disappearance of sadness and joy. One enters and abides in the fourth jhana. Which has neither pleasure nor pain. And has mindfulness purified and born of equanimity.'
Once the mind has been made malleable and peaceful from samhadi. There is an afterglow, where unwholesome states of mind can remain absent for some time. In that state, the mind has the capacity for wise reflection, and it is easy to work with and train. It can be pointed towards something you want to understand and learn more about, or a truth you want to penetrate and gain insight from, such as the four noble truths. This investigation can lead to the liberating knowledge that brings about the end of suffering.
The continuous practise of jhana gradually weakens the hold of greed and hatred on the mind until eventually those defilements fall away for good and never return. When this happens one becomes a non-returner, (the third stage of enlightenment) and is never again born into this world.
Full enlightenment (fourth and final stage) is the realisation of nibanna, and the complete end of the conceit 'I am' and delusion.