The early Kadampas would often say that to lead a virtuous life all we need to do is harm our delusions as much as possible and benefit others as much as possible. Understanding this, we should wage continuous warfare against our inner enemy of self-cherishing and strive to cherish and benefit others instead. (Geshe Kelsang Gyatso, Eight Steps to Happiness: the Buddhist Way of Loving Kindness, p. 99, © 2000)
To “harm our delusions as much as possible,” we cultivate renunciation and practice according to the Pratimoksha vows we have taken; and to “benefit others as much as possible,” we generate bodhichitta and practice according to our Bodhisattva vows. Monastic discipline (Skt. Vinaya) falls under the Pratimoksha vows. The emphasis in monastic life should be placed, not on its external forms (i.e., the outer Vinaya), but on the mind of renunciation which is formless (i.e., the inner Vinaya). Legalistic attachment to a certain number of vows completely misses the point, for as Milarepa said, “I do not know the Vinaya, but I know how to control my mind.”
No matter the number of precepts taken, this number is merely symbolic, for the real intention is to abstain from all non-virtuous actions, meaning that the 10 vows taken are actually infinite in scope. Regarding this simplified presentation, Geshe-la has said that “The actual words of the Kadampa ordination are brief but the practice is very extensive.” Because the Kadampa ordination emphasizes quality over quantity, it certainly preserves the innate principles of the Vinaya. The ordination vows of monks and nuns in the New Kadampa Tradition are to:
- abandon killing
- abandon stealing
- abandon sexual activity
- abandon lying
- abandon taking intoxicants
- practice contentment
- reduce one’s desire for worldly pleasures
- abandon engaging in meaningless activities
- maintain the commitments of refuge
- practise the three trainings of pure moral discipline, concentration, and wisdom
Strictly speaking, “The prerequisite for achieving liberation or full enlightenment, or even for ordination as a monk or nun, is the mind of renunciation” (Meaningful to Behold: Becoming a Friend of the World, p. 158). Renunciation is the definite wish to be released from samsara. Without this spiritual realization of renunciation as its foundation, one technically cannot even train in higher moral discipline (i.e., the Vinaya), and so until such time, any ordained person’s Pratimoksha vows remain provisional. That is to say, when one’s motivation is artificial, then the vows taken with such a motivation are necessarily artificial too. The same can be said of one’s Bodhisattva vows:
Before generating actual, spontaneous bodhichitta and becoming a Bodhisattva, a Mahayana practitioner will spend a long time cultivating a strong wish to become a Buddha for the benefit of all living beings. This cultivated mind is called ‘bodhichitta’, but it is not actual bodhichitta. Actual bodhichitta is necessarily a spontaneous mind that arises without effort. In Sutra Requested by Those with Superior Intention Buddha says that the cultivated mind is like the bark of sugar cane whereas the spontaneous mind is like its core. The bark of sugar cane tastes sweet, but it is not as sweet as the core. (Geshe Kelsang Gyatso, Ocean of Nectar: the True Nature of All Things, pp. 18-19, © 1995)
According to the tradition of Geshe Potowa (1031-1105 CE), once real, non-fabricated renunciation is generated, one’s ability to practice higher moral discipline comes within reach, and then the renunciate’s initial vows (Tib. Rabjung) naturally transform into real ordained vows, albeit novice vows (Skt. Shramanera, Tib. Getsul). Later, when spontaneous renunciation arises in one’s heart day and night, one can then fully practice the path to liberation, and it is in this sense that Geshe-la uses the words “fully ordained” (Skt. Bhikkshu, Tib. Gelong).
See also Are the NKT vows an authentic presentation of the Vinaya? 
With the motivation of renunciation, when we practise any moral discipline—from the moral discipline of abandoning killing to the moral discipline of keeping all three sets of vows, the Pratimoksha, Bodhisattva, and Tantric vows—we are practising higher moral discipline. Without the motivation of renunciation any practice of moral discipline is a cause of higher rebirth in samsara, but it is not a cause of liberation.
In Friendly Letter Nagarjuna says:
Always practise superior moral discipline,
Superior concentration, and superior wisdom.
These three perfectly include
All the two hundred and fifty-three trainings.
Fully ordained monks take two hundred and fifty-three vows, and all of them are contained within the practise of higher moral discipline because they are taken with the motivation of renunciation. The same applies to the Bodhisattva and Tantric vows. If we take the Pratimoksha vows before developing renunciation our vows are not actual but provisional Pratimoksha vows. If we subsequently listen to, contemplate, and meditate on the stages of the path we shall develop the realization of renunciation. When this happens our provisional Pratimoksha vows are transformed into real Pratimoksha vows. Geshe Potawa used to say ‘Dromtonpa is my ordaining Abbot.’ Since Dromtonpa was a layman he could not actually be an ordaining Abbot. Geshe Potawa was implying that it was due to Dromtonpa’s guidance that he developed the realization of renunciation and thus transformed his provisional monk’s vows into real ones.
Through this we can understand clearly how important it is for those who have received the Pratimoksha, Bodhisattva, and Tantric vows to practise Lamrim. If we neglect the practice of Lamrim it is almost impossible these days for us to keep our vows purely without breaking them. (Geshe Kelsang Gyatso, Joyful Path of Good Fortune: the Complete Buddhist Path to Enlightenment, pp. 368-369, © 1990, 1995)