I always say the essence of philosophy is inquiry and exploration into the most deep, profound, and universal questions and subjects.
I'd also say there has to a be a certain amount of rational thought put into it. I hesitate to say "rational" because it's not all about dry, straightforward reasoning and rationalism is insufficient/misguided, but it should be well-thought out, maybe elaborate, and not *irrational* per se. (What's irrational seems to be a matter of perspective, but I guess I mean, again, it should be well- thought out, maybe even intelligent (though I'm not sure if we should be intellectual elitists when it comes to who can philosophize), coherent, and preferably self-consistent (though on the other hand, I argue why we should be more comfortable with contradiction here https://philosophy.inhahe.com/.../why-we-should-be-more.../).)