(Sanskrit बोधिचित्त; often spelled bodhicitta, but pronounced "boh-dee-cheeta") Literally, Bodhi means "enlightenment, wisdom." Chitta means "mind, heart, aim." In synthesis, bodhichitta means the enlightened psyche or the psyche of wisdom. This term has many levels of application.
"Whatever joy there is in this world
All comes from desiring others to be happy,
And whatever suffering there is in this world,
All comes from desiring myself to be happy.
But what need is there to say much more?
The childish work for their own benefit,
The Buddhas work for the benefit of others.
Just look at the difference between them!" —Shantideva
"Bodhicitta or the altruistic aspiration to attain enlightenment for the benefit of all sentient beings is a state of mind which cannot be cultivated or generated within one's mental continuum simply by praying for it to come into being in one's mind. Nor will it come into existence by simply developing the understanding of what that mind is. One must generate that mind within one's mind's continuum. In order to engage in meditation with sustained effort over a period of time what is crucial is first of all to be convinced of the positive qualities of that mind, and the benefits and merits of generating such a state of mind. It is only when one has seen the qualities, merits and benefits of generating such a state of mind that one will be able to generate within oneself a genuine enthusiasm and perseverance in engaging in a meditation which would enable the individual to generate the mind." —The 14th Dalai Lama
"The Bodhichitta is the awakened and developed superlative Consciousness of the Being. The Bodhichitta emerges in the aspirant who sacrifices himself for his fellowmen, long before the Mercurial bodies have been created... It is necessary for the Bodhichitta, which means the auric embryo, the awakened consciousness, to fall into the Illuminated Void." - Samael Aun Weor, The Gnostic Bible: The Pistis Sophia Unveiled
"Obviously, before the Bodhisattva is born, the Bodhichitta must be formed within ourselves. Furthermore, it is important to clarify the necessity of disintegrating the ego, the “I,” in order for the Bodhichitta to emerge. The Bodhichitta is formed with the merits of love and supreme sacrifice for our fellowmen. The Bodhisattva is formed within the environment and psychological atmosphere of the Bodhichitta." - Samael Aun Weor, The Gnostic Bible: The Pistis Sophia Unveiled
"The one who does not possess the Bodhichitta, even when he has created the superior existential bodies of the Being, is still unconscious and absurd." - Samael Aun Weor, The Gnostic Bible: The Pistis Sophia Unveiled
It is worth noting that since the bodhisattva is formed in the atmosphere of the bodhichitta, we can see that outcome in the word bodhichitta itself: bodhi represents the Christ / Avalokitesvara that incarnates in the bodhisattva, while chitta (mind, heart, aim or will) indicates the solar bodies that gve it expression.