Notes on conditional logic

This paper consists of some lecture notes in which conditional logic is treated as an extension of modal logic. Completeness and filtration theorems are provided for some basis systems. These notes were originally drafted for a course given at the University of Auckland in 1987 (Philosophy 29.308). The work reported in Section 5 is due to Michael Strevens, who took the course and presented his conception of a filtration in a term paper [5]. The author wishes to thank Strevens for many stimulating discussions and for permission to include his results here