With the ecstasy of compassion in devotional service, a mixture of anger or parental love is compatible; while a mixture of laughter, conjugal love or astonishment is always incompatible.
With the ecstasy of anger in devotional service, a mixture of compassion or chivalry is compatible; while a mixture of laughter, conjugal union or dread is completely incompatible.
With the ecstasy of dread in devotional service, a mixture of ghastliness or compassion is compatible.
With the ecstasy of chivalry in devotional service, a mixture of conjugal union, laughter or anger is always incompatible.
In the ecstasy of ghastliness in devotional service, feelings of neutral love, laughter or servitude are compatible; whereas feelings of conjugal union and fraternity are incompatible.
The above analysis is a sample of the study of rasābhāsa or incompatible mixing of rasas. This transcendental science of rasābhāsa can thoroughly explain the humors in ecstatic love which are compatible and incompatible with one another. When Lord Caitanya Mahāprabhu was residing in Jagannātha Purī, many poets and devotees used to come to Him and offer their different kinds of poetry, but the regulation was that Lord Caitanya's secretary, Svarūpa Dāmodara, first examined all of these writings scrutinizingly, and then if he would find that there were no incompatibilities in the rasas, or transcendental mellows, he would then allow the poet to approach Lord Caitanya and recite his poetry.
The topic of incompatibility is a very important one, and those who are pure devotees always expect to find perfect compatibility in descriptions of the different relationships with the Personality of Godhead. The study of compatibility and incompatibility sometimes becomes very involved, and a hint of why this is so is given as follows: When a friend meets another friend, the mellow produced out of that meeting is generally taken as very palatable. But actually with such meetings between two friends, there are so many feelings involved that it is difficult to ascertain when these feelings are actually becoming compatible and when they are becoming incompatible.