An attempt at alteration and supplementation: assume that I would be just as I am, that I would have been just as I was, and that I would be in the future just as I will be; assume that in all this there is nothing lacking by way of my perceptions pertaining to the five senses or any other perceptions in general; nothing lacking by way of my apperceptive processes, none of my conceptual thoughts, none of my imagination and thoughts, none of my imaginations and thought experiences, or any of my experiences in general — assume all of them in their concrete fullness, in their determinate arrangements and connections; what would prevent there from being simply nothing at all in addition to them? Could not an all-powerful God or a deceitful spirit have so created my mind and supplied it with mental content that nothing exists of all the objectivities that are meant within it insofar as they are extra-menta? Perhaps things do exist outside of me, but not one of those that I take to be real. And perhaps there is nothing outside me at all.