 Thus, at some level the noise will be noticed. Leibniz is silent on precisely how this threshold is determined. Although he frequently claims that differences in kind (although continuous with other kinds) arise at the infinite or the infinitesimal, this is in tension with many of the phenomena of consciousness which apparently arise at some mid-level degree of perceptual distinctness (as with the description of the difference between a conscious perception of light and an unconscious perception of light above). Here is another area where Leibniz is offering a theory and is optimistic that the relevant natural factors determining the threshold will be discovered in the science of pneumatology (and, indeed, cognitive science has made some progress in this direction). 