This refers to the first Hermetic principle, Mentalism, which states that all is mind. 'The All is Mind; the universe is mental.'—The Kybalion. I laughed when I first read it, interpreting 'mental' as 'mad' (crazy), which often seems not so far from the truth, really, and that's a good thing.
The thingy below the maxim is a symbol I created to represent infinite love.