The regulative principlec of reason in regard to this problem of ours is therefore that everything in the world of sense has an empirically conditioned existence, and there cannot be an unconditioned necessity in it in regard to any of its properties, that there is no member of the series such that one does not always expect an empirical condition for it in a possible experience, and for which one must seek for such a condition as far as one can, and nothing justifies us in deriving any existence from a condition outside the empirical series, or indeed in taking any thing in the series itself to be absolutely independent and self sufficient; nevertheless, this is not in any way to deny that the entire series could phenomenal substance a being outside the world