Abstract
Science is punctuated with Physical Phenomena (such as lightning and lode stones), and Phenomenal Phenomena (such as illusions and consciousness). The physical sciences have benefited by classifications; but perception lacks corresponding classification of its phenomenal phenomena. An attempt at classification —by kinds and causes — will be presented and discussed. It is hoped this ‘Peeriodic Table’ may help to structure the subject; suggest experiments; help to interpret results, and reveal gaps in our knowledge and understanding. Discussing explicit ‘litmus tests’ for assigning phenomena to categories may be useful for showing up theoretical disagreements, and so aid communication within our subject.