This says that 'Absolute universalism, in which we feel compassion for every individual on Earth, is psychologically impossible' because we need to be able to hate on out-groups to love on in-groups. If we discover aliens might this not hold?
It's not impossible but it requires a long sincere practice to peel off the layers of false identities that we associate ourselves with. These are gradually created starting right from our birth.
However one way it's true because once compassion for all beings (not just humans) becomes our nature, we no longer remain human – we become divine.
That's the goal of all paths of Yoga (Karma/devotion/meditation/wisdom)
The above isn't something theoretical jargon – I know at least one individual living at this moment who has reached to that state by following the meditation path of yoga [0].
As an antidote to this echo chamber effect, I invite proselytizers to discuss their ideas in a non-proselytizing way, so that we can meet on common ground instead of assuming vague terms like "divine" etc. If we can't get to that point, it's just one echo chamber talking to another.
Yoga comes under psychology and spirituality, not religion. it's not related to rituals but introspection within – examining and experiments with your mind (habit patterns, emotions and thoughts). Just like a scientist does with nature externally. Only tools of the trade are different.
You may wish to read yoga sutras on swamij.com to see for yourself the profound insights of mind and its working expounded by the author Patanjali.
For instance, Yoga sutras starts with:The goal of Yoga is to regulate the modifications (tendencies) of mind,So the seer rests in its true nature.
The true nature of our consciousness (the seer) is existence-knowledge-bliss.
Hating someone or a group/race of beings is just a negative tendancy which has been adopted, often unconsciously, due to certain experiences in life. With stillness of meditation you can invite such thoughts witness them and remove clinging of mind toward them [0]. All methodologically.
Of course telling people how to attain special divinity through holy practices is proselytizing... sure, we can call it spiritual proselytizing!
Since you give me life recommendations and profound wisdom, here's my advice offered in return: forget about all this stuff and just live your life as an ordinary human on earth.
Through this simple practice of letting go of attachment to religious hope, you can find a sweet kind of freedom and simplicity—maybe even some kind of wisdom!