in his discourses concerning perception of universals, mullā ṣadrā has brought up various issues. on one hand, he says that in sensory and imaginative perceptions, the soul (nafs) is the originator and creator of images and then with its substantial and ontogenetic motion it achieves its higher level of perception, i.e. rational perception, unites with the rational non-material substance named ...

TO THE EDITOR: We thank those colleagues (see Ref. 1) who have taken the time to comment on our Viewpoint. Our interpretation of these comments is that there is general agreement that there remain uncertainties about how peripheral lung structure changes with lung inflation and deflation. We focused on a simple experiment that measured a mean linear dimension in the peripheral lung, and althoug...