In his Guide to the Perplexed-First Part Chapter 74 seventh argument, Rambam says:
You must bear in mind that those abstract beings which are neither bodies nor forces dwelling in bodies, and which in fact are ideals—are altogether incapable of being represented as a plurality unless some ideals be the cause of the existence of others, and can be distinguished from each other by the specific difference that some are the efficient cause and others the effect; but that which remains of Zaid [after his death] is neither the cause nor the effect of that which is left of Amr, and therefore the souls of all the departed form only one being as has been explained by Ibn Bekr Ibn Al-zaig, and others who ventured to speak on these profound subjects.
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Now, the theory of monopshichism maintains that the individual soul is therefore not immortal in itself, but perishes together with the body, resulting in a sort of "osmosis" in the hereafter among all souls, which therefore lose their individuality. I wonder therefore: but according to Rambam, then, in what sense do the souls of the righteous live eternally at HaShem in the olam ha ba?
