From the notes of a person in attendance at an Esoteric Lesson given by Rudolf Steiner in Stuttgart on May 18, 1913:
... so that what comes from the series of incarnations and generations can come together, forces are at work above the Moon forces — the Mercury forces. We also got our intellect that's bound to the brain from them. And when we look toward Mercury, and generally whenever we use our intellectual forces, we should fill ourselves with thanks to these beings who gave them to us. But there's something still higher than mere intellect. If new, creative ideas hadn't flowed in, evolution would always have stayed at the same point. School children learn things today that wise Pythagoreans didn't know yet, and these new things that are continually flowing in come from a sphere above Mercury, from Venus. The creative thoughts that become manifest in inventions flow into evolution through it. This is the only thing that makes progress possible. This thinking isn't brain-bound, it's lighter and has more feeling to it.