If you have time, I'm trying to understand why is bodhicitta given such a prominent role in Mahayana and I'm wondering how is bodhicitta different from the paramis (if it is at all)? I mean, to me bodhicitta seems like an amalgamation of three theravadin paramis of adhitthana (determination, resolution), wisdom and metta.
Reading about paramitas on wikipedia, though only six are listed for Mahayana, it is also stated that Dasabhumika sutra adds four paramitas more of which pranidhana (vow, resolution, aspiration, determination) is one, and it seems to correspond to theravadin adhitthana parami. Further, reading about bodhicitta on wikipedia, the first definition is that it is the wish to attain complete enlightenment (buddhahood), so I'm wondering how is this wish aspect of bodhicitta different from adhitthana?
Since my knowledge and experience are both very limited I can only try to repeat what I have been taught and take the responsibility for any error.
There are several aspects of bodhicitta that are given different qualifying names: conventional and ultimate bodhicitta, aspirational and engaging bodhicitta.
"conventional" refers to conventional reality expressed in words and thought.
"ultimate" refers to the direct realization of emptiness.
"aspirational" refers to the mere wish.
"engaging" refers to taking the vow and learning, practicing the paramitas.
So actually the "conventional" comprises the "aspirational" and the "engaging" whereas the "ultimate" refers to the wisdom that is the culmination of the practice of the 6th paramita.
On Dharma Wheel
Ven. Huifeng has provided a quote which covers both, the conventional and the ultimate aspect of bodhicitta:
An excellent example of what is meant by bodhicitta is to be found in the Vajracchedika Prajnaparamita Sutra (aka: the Diamond Sutra). Conze's translation has:
The Lord said: Here, Subhuti, someone who has set out in the vehicle of a Bodhisattva should produce a thought in this manner: 'As many beings as there are in the universe of beings, comprehended under the term "beings" egg-born, born from a womb, moisture-born, or miraculously born; with or without form; with perception, without perception, and with neither perception nor non-perception, as far as any conceivable form of beings is conceived: all these I must lead to Nirvana, into that Realm of Nirvana which leaves nothing behind. And yet, although innumerable beings have thus been led to Nirvana, no being at all has been led to Nirvana.' And why? If in a Bodhisattva the notion of a 'being' should take place, he could not be called a 'Bodhi-being'. 'And why? He is not to be called a Bodhi-being, in whom the notion of a self or of a being should take place, or the notion of a living soul or of a person.'
It involves the compassion to lead beings to nirvana, and also the wisdom of emptiness that sees that ultimately there is no "living being".
Now the crucial point is the altruistic intention
which is directed towards all other beings and that the wisdom aspect does not negate this "directedness". This "altruism being directed towards others" is the mark of the path and must not be abandoned at any time, because the moment it is abandoned in the context of [motivation for] practice
one immediately lapses from the path of the bodhisattva. "Mindfulness" for a bodhisattva also means to permanently hold bodhicitta in his/her mind and to practice on the basis of bodhicitta and dedicate any result of practice to perfect buddhahood for the benefit of other beings which actually means to give all "merits" that may have been collected by means of practice to other beings (which is an aspect of the 1st paramita).
The second definition of bodhicitta is that it is the union of compassion and wisdom, so I'm wondering how it is different from the two theravadin paramis of wisdom and metta? I understand that it could be said that metta isn't exactly karuna, but, if considered that non-aversion as one of the kusala roots is in essence the base of metta, and that karuna as a kusala cetasika can only accompany a kusala citta with non-aversion as one of the roots, and that one can extended mahametta and mahakruna with attaniment of (if I'm not mistaken) fourth jhana, it seems then that these two paramis of wisdom and metta in developed form are equivalent to bodhicitta.
The basis of conventional bodhicitta actually are the four immeasurables:
- impartiality (sometimes called "equanimity") and the intention to "give" this impartiality to others because partiality is the root of samsara
- love which is the wish and the intention to give happiness to others and to provide/train all the causes for happiness
- compassion which is the wish and the intention to eliminate other's suffering and the causes
- prevent that others undergo lower "re-births" and establish them in liberation through skillful means
A type of "union of compassion and wisdom" may be the merging of prajnaparamita and altruistic bodhicitta (manifested in the "method aspect" of the paramitas) on the 8th bhumi and the following. The 8th bhumi is said to be point where the practitioner achieves either liberation/cessation of an arhat if bodhicitta has been abandoned in the course of the path and has not been re-established or she/he continues further to the 10th level if bodhicitta has been kept "intact". More experiential presentations of this "union" one may find in the vajrayana.