its jurisdiction, or venturing into an area under provincial jurisdiction. The legal effect refers to how the law will affect rights and liabilities, and is also helpful in illuminating the core meaning of the law: see Reference re Firearms Act. The effects can also reveal whether a law is colourable (does the law in form appear to address something within the legislature's jurisdiction, but in substance deal with a matter outside that jurisdiction?). For example, in R. v. Morgentaler (1993), the province of Nova Scotia passed a law that prohibited certain surgical procedures from being performed outside of hospitals under the guise of health services protection. The Supreme Court of Canada ruled that in substance, the province was attempting to ban abortions. The pith and substance analysis is not technical or formalistic it is essentially a matter of interpretation. The court looks at the words used in the impugned legislation as well as the background and circumstances surrounding its enactment. In conducting this analysis, the court should not be concerned with the efficacy of the law or whether it achieves the legislature’s goals. Assignment There are two significant principles to be used in determining whether a matter falls within a particular federal or provincial jurisdiction: The Constitution must be interpreted flexibly over time to meet new social, political and historic realities The principle of federalism must be respected, keeping in mind: Power is shared by two orders of government, each autonomous in developing policies and laws within their own jurisdiction Classes of subjects should be construed in relation to one another In cases where federal and provincial classes of subjects contemplate overlapping concepts, meaning may be given to both through the process of “mutual modification” Classes of subjects should not be construed so broadly as to expand jurisdiction indefinitely Once the law has been characterized it must be assigned to one of the two heads of power. The matters in the exclusive domain of the federal government are enumerated under section 91 of the Constitution Act, 1867 and matters in the exclusive domain of the provincial government are enumerated under section 92. Whether the characterization of a law fits within one of the enumerated matters depends on the breadth given by the court to each matter. A law found to be valid under the pith and substance analysis of the law may also have some incidental effects upon matters outside