But since he could not explain at all how it is possible for the understanding to think of concepts that in themselves are not combined in the understanding as still necessarily combined in the object, and it never occurred to him that perhaps the understanding itself, by means of these concepts, could be the originator of the experience in which its objects are encountered, he thus, driven by necessity, derived them from experience (namely from a subjective necessity arisen from frequent association in experience, which is subsequently falsely held to be objective,.e., custom);e