The drug MDMA, commonly known as ecstasy, produces a specific and distinct open hearted mental state, which led to the creation of a new pharmacological class, “entactogens”. Extensive literature on its mechanisms of action has come to characterize MDMA as a “messy” drug with multiple mechanisms, but the consensus is that the distinctive entactogenic effects arise from the release of neurotransmitters, primarily serotonin. I propose an alternative hypothesis:

• The entactogenic mental state is due to the simultaneous direct activation of imidazoline-1 (I 1 ) and serotonin-2 (5-HT 2 ) receptors by MDMA.

This hypothesis emerges from “mental organ” theory, which embodies many hypotheses, the most relevant of which are:

• “Mental organs” are populations of neurons that all express their defining metabotropic receptor, and each mental organ plays a distinct role in the mind, a role shaped by evolution as mental organs evolve by duplication and divergence. Mental organs are the mechanism by which evolution sculpts the mind. • Mental organs can be in or out of consciousness. • In order for a mental organ to enter consciousness, three things must happen: ○ The mental organ must be activated directly at its defining receptor. ○ 5-HT 2 must be simultaneously activated. One of the functions of activated 5-HT 2 is to load other simultaneously activated mental organs fully into consciousness. ○ In some cases THC must be introduced to remove long-term blocks mediated by the cannabinoid system.