 All the elements from Kant’s earlier discussion of causality in the essays on Negative Magnitudes and Dreams of a Spirit-Seer seem to be present here. Kant begins with the purely logical relation between ground and consequent. Since, in the case of the concept of cause, we are dealing with what Kant had earlier called a real ground, Kant holds that we need a synthetic rather than merely analytic connection between the two. The most obvious thought, which Hume had defended in the Enquiry (and, apparently following Hume, Kant himself had defended in Dreams of a Spirit-Seer) is that “experience” (in the Humean sense) is the basis for this connection in so far as one perception is found to be “constantly conjoined” with another. Now, however, in the critical period, Kant introduces a revolutionary new concept of “experience” which is explicitly opposed to mere constant conjunctions among perceptions in being “necessary and universally valid”—in particular, “experience is possible only by means of the representation of a necessary connection of perceptions” (B218).