Smart and the secondary qualities, Professor D.M.Armstrong; laws coincidences and relations between universals, Dr L.J.Cohen; the ontology of scientific realism, Professor Brian Ellis; why moral language?, Professor R.M.Hare; group morality, Professor Frank Jackson; the singularly affecting facts of causation, Dr D.H.Mellor; the diversity of the sciences, Professor Hilary Putnam; life's uncertain voyage, Professor Peter Singer; replies, Professor J.J.C.Smart.