Calalang vs. Williams
The classic case of Calalang vs. Williams, 70 Phil. 726 (1940), tackled the issue of police power for public welfare, but is remembered because it contains a definition of social justice.
Was the regulation valid?
Yes. The Supreme Court upheld the regulation as a valid exercise of police power in the interest of public welfare.
This case is known primarily for the words of Justice Jose P. Laurel defining social justice: :