6/8/2020 E-Library - Information At Your Fingertips: Printer Friendly which normally constitutes an actionable wrong.[12] Nevertheless, no right is absolute, and the proper regulation of a profession, calling, business or trade has always been upheld as a legitimate subject of a valid exercise of the police power by the state particularly when their conduct affects either the execution of legitimate governmental functions, the preservation of the State, the public health and welfare and public morals. According to the maxim, sic utere tuo ut alienum non laedas, it must of course be within the legitimate range of legislative action to define the mode and manner in which every one may so use his own property so as not to pose injury to himself or others.[13] In any case, where the liberty curtailed affects at most the rights of property, the permissible scope of regulatory measures is certainly much wider.[14] To pretend that licensing or accreditation requirements violates the due process clause is to ignore the settled practice, under the mantle of the police power, of regulating entry to the practice of various trades or professions. Professionals leaving for abroad are required to pass rigid written and practical exams before they are deemed fit to practice their trade. Seamen are required to take tests determining their seamanship. Locally, the Professional Regulation Commission has began to require previously licensed doctors and other professionals to furnish documentary proof that they had either re-trained or had undertaken continuing education courses as a requirement for renewal of their licenses. It is not claimed that these requirements pose an unwarranted deprivation of a property right under the due process clause. So long as Professionals and other workers meet reasonable regulatory standards no such deprivation exists. Finally, it is a futile gesture on the part of petitioners to invoke the non-impairment clause of the Constitution to support their argument that the government cannot enact the assailed regulatory measures because they abridge the freedom to contract. In Philippine Association of Service Exporters, Inc. vs. Drilon, we held that "[t]he nonimpairment clause of the Constitution... must yield to the loftier purposes targeted by the government."[15] Equally important, into every contract is read provisions of existing law, and always, a reservation of the police power for so long as the agreement deals with a subject impressed with the public welfare. A last point. Petitioners suggest that the singling out of entertainers and performing artists under the assailed department orders constitutes class legislation which violates the equal protection clause of the Constitution. We do not agree. The equal protection clause is directed principally against undue favor and individual or class privilege. It is not intended to prohibit legislation which is limited to the object to which it is directed or by the territory in which it is to operate. It does not require absolute equality, but merely that all persons be treated alike under like conditions both as to privileges conferred and liabilities imposed.[16] We have held, time and again, that the equal protection clause of the Constitution does not forbid classification for so long as such classification is based on real and substantial differences having a reasonable relation to the subject of the particular legislation.[17] If classification is germane to the purpose of the law, concerns all members of the class, and applies elibrary.judiciary.gov.ph/thebookshelf/showdocsfriendly/1/34037 6/8