three tattvas

On page 116 in Rangjung Yeshe's "The Light of Wisdom" (ISBN 9627341371), vol. 1, of The Essence of Generating Bodhichitta, it says in regard to Asanga's System of Bodhichitta: "There are four different types of stages, from the devoted engagement of ordinary people up through buddhahood. Although twenty-two types are taught using analogies in terms of their characteristics, the following two divisions are easy to understand and more well known.

The bodhichitta of aspiration, resembling the wish to travel, means desiring to attain, or, more appropriately, to reveal buddhahood. The bodhichitta of application, resembling actually traveling, means exerting oneself in the two kinds of bodhichitta...the means for attaining [revealing] buddhahood.

These are the two types defined according to their characteristics, aspiration, and application: the bodhicitta of aspiration is the four immeasurables, and the bodhichitta of application is the six paramitas.

According to the system of Nagarjuna, the bodhichitta of aspiration is to pledge the effect, and the bodhichitta of application is to pledge the cause.

So here is also the system of Asanga, according to which the intention is the bodhichitta of aspiration, and the engagement is the bodhichitta of application. The bodhichitta of aspiration is the wish to attain [reveal] buddhahood, like intending to travel. The bodhichitta of application is to train in bodhichitta, the means for attaining [revealing] buddhahood...like actually traveling.