Rambam understands that even the suggestion that the cosmos is controlled by “spirits” and therefore these spirits have an impact on how things are in our world is forbidden. It is nonsense and lies and whoever believes that is a fool. When we try to understand how the cosmos works, we can explain it as a physical phenomenon or as a spiritual one. Starting from a standpoint that there is no such thing as “spiritual” or non-physical powers, one is forced to look for explanations that can be proven empirically. It is the belief in “spirituality” which is the greatest obstacle in the scientific understanding of our world. It is much easier to explain things by attributing phenomena to “spiritual” powers.
Contrast this to, say, the Ramchal in "Derech Hashem" who basically says that every natural phenomenon is controlled by an angel (a "non-physical" being). I don't want to rehash this, but short of some serious kvetching, I cannot see these two opinions reconcile. They cannot both be right.
On another note, some commenter on Hirhurim afterlife thread mentioned that the phrase "Na'aseh Adam" in the Torah clearly implies a Heavenly Court:
It's quite clear from the Torah- right from the start- that there's a heavenly Court. ("Na'aseh Adam" etc.) Why wouldn't righteous neshamot go there?I don't know if he means that the New Testament takes the idea of a Heavenly Court for granted in general, or because of the phrase "Na'aseh Adam". I think it is ironic, because that phase had always been used by Christians to "prove" the notion of the Trinity - who else can the Bible mean when it says "Let us make man"? And it is further ironic that the same phrase is used by anti-religious people to "prove" that this language is a vestige of polytheism.
(Not sure if this counts, but the New Testament takes it for granted. That's still hundreds of years after the era of Tanach, but it would seem to indicate that it was a common belief among Jews then.)