Metaphysical Tracts by English Philosophers of the Eighteenth Century Consisting of 1. Clavis Universalis; 2. A Specimen of True Philosophy, by Arthur Collier; 3. Conjecturae Quaedam de Sensu, Motu, Et Idearum Generatione; 4. An Inquiry Into the Origin of Human Appetites and Affections; 5. Man in Quest of Himself