The issuance of postage stamps by the government, even if related to an event with religious significance, does not violate the constitutional prohibition against the appropriation of public funds for the use, benefit, or support of any sect or church, provided that the primary purpose of such issuance is secular (e.g., promoting the country, tourism, or commemorating an event of national or international interest) and any benefit accruing to a religious institution is merely incidental and not the direct aim of the governmental action.

The case arose from the decision of the Director of Posts in May 1936 to issue and sell postage stamps commemorating the Thirty-third International Eucharistic Congress, an event organized by the Roman Catholic Church and scheduled to be held in Manila. This action was perceived by the petitioner, the head of another religious denomination, as an unconstitutional use of public resources to favor a specific church, leading to the legal challenge.

• In May 1936, the respondent, Juan Ruiz, Director of Posts, announced the plan to issue postage stamps commemorating the Thirty-third International Eucharistic Congress, an event organized by the Roman Catholic Church in Manila.
• The petitioner, Mons. Gregorio Aglipay, Supreme Head of the Philippine Independent Church, formally protested this issuance through his attorney, denouncing it to the President of the Philippines as a violation of civic duty.
• Despite the protest, the Director of Posts proceeded, announcing that the designs had been sent to the United States for printing; the stamps were subsequently issued and sold.
• The initially planned design featuring a chalice was altered; the actual stamps depicted a map of the Philippines, the location of the City of Manila, and an inscription: "Seat XXXIII International Eucharistic Congress, Feb. 3-7, 1937."
• The Director of Posts justified the issuance under Act No. 4052, which appropriated P60,000 for new postage stamp designs and authorized their issuance when deemed "advantageous to the Government."
• The stated purpose for issuing the stamps, according to government officials, was "to advertise the Philippines and attract more tourists to this country" and "to give publicity to the Philippines and its people" by leveraging an event of international importance.
• The respondent estimated significant revenue from the sale of these stamps and stated that a large quantity remained unsold.

• The petitioner argued that the issuance and sale of postage stamps commemorating the Thirty-third International Eucharistic Congress, an event specific to the Roman Catholic Church, violated Section 13, Subsection 3, Article VI of the Philippine Constitution, which prohibits the appropriation, application, or use of public money or property, directly or indirectly, for the use, benefit, or support of any sect, church, denomination, or sectarian institution.
• The petitioner contended that this act constituted an unconstitutional use of government resources to favor and support a particular religious denomination.

• The respondent, represented by the Solicitor-General, argued that a writ of prohibition, while generally not for non-judicial functions, could restrain ministerial functions performed without or in excess of jurisdiction, and an act violative of the Constitution would fall under this.
• The respondent maintained that the issuance of the stamps was authorized by Act No. 4052, which empowered the Director of Posts to issue new stamp designs when "advantageous to the Government."
• The primary purpose of the stamps, according to the respondent, was not to benefit the Roman Catholic Church but to promote the Philippines, attract tourism, and publicize Manila as the host of an internationally significant event.
• Any benefit derived by the Roman Catholic Church was claimed to be merely incidental to this primary secular purpose.
• The respondent also highlighted potential financial losses to the government if the sale of the already printed stamps was halted.

• Whether the issuance and sale of postage stamps by the Director of Posts commemorating the Thirty-third International Eucharistic Congress constituted a violation of the constitutional prohibition against the use of public funds or property for the benefit or support of any church, sect, or system of religion.
• Whether a writ of prohibition is the appropriate legal remedy to prevent the Director of Posts from continuing the issuance and sale of the said stamps.

• The Supreme Court denied the petition for a writ of prohibition.
• The Court first affirmed that a writ of prohibition, under Philippine statutes (Sections 516 and 226, Code of Civil Procedure), can be issued against an officer performing ministerial functions if their acts are without or in excess of jurisdiction, especially if alleged to be unconstitutional.
• On the substantive issue, the Court held that there was no constitutional violation. Act No. 4052, authorizing the stamps, did not specify a religious purpose but granted discretion to issue stamps when "advantageous to the Government."
• The Court found that the government's primary intention in issuing the stamps was secular: to advertise the Philippines, attract tourists, and highlight Manila as the venue of an international congress. This was supported by the stamp design, which emphasized Manila as the "Seat" of the Congress and featured a map of the Philippines, rather than purely religious iconography.
• The Court reasoned that any propaganda or benefit the Roman Catholic Church might receive from the stamps was incidental to this legitimate secular purpose and not the government's aim. The government should not be hindered in its legitimate activities merely because of such incidental religious consequences.
• The Court concluded that even if the decision to issue the stamps represented poor judgment by the officials, it did not rise to the level of a constitutional infraction.

• Separation of Church and State — This fundamental principle posits that the State shall not establish any religion, endorse any religion, or unduly interfere with the free exercise of religion, and religious bodies shall not control the State. The Court identified the constitutional prohibition against using public funds for sectarian purposes (Art. VI, Sec. 13(3)) as a direct corollary of this doctrine. It was applied to determine if the stamp issuance breached the wall of separation by favoring one church.
• Religious Liberty — The constitutional right of individuals to practice their chosen religion, or no religion, without government compulsion or preference. The Court emphasized that the Philippine Constitution guarantees "religious liberty, not mere religious toleration." This principle informed the Court's understanding of the limits on government action in areas touching upon religion.
• Primary Purpose Test / Incidental Benefit Doctrine — A government action that may provide some benefit to a religious institution is not unconstitutional if its primary purpose is secular and the benefit to religion is indirect and incidental, rather than the direct aim of the action. The Court applied this by finding the primary purpose of the stamps was to promote the Philippines (a secular goal), and any benefit to the Catholic Church was merely an incidental outcome, not a constitutional violation.
• Scope of Writ of Prohibition — An extraordinary writ that, in Philippine jurisdiction, is not limited to restraining judicial or quasi-judicial functions but can also be issued against officers or persons performing ministerial functions if their acts are without or in excess of their authority, particularly when such acts are challenged as unconstitutional. The Court affirmed its applicability to the Director of Posts, whose act was alleged to be unconstitutional.

• "The prohibition herein expressed is a direct corollary of the principle of separation of church and state."
• "It should be stated that what is guaranteed by our Constitution is religious liberty, not mere religious toleration."
• "The officials concerned merely took advantage of an event considered of international importance 'to give publicity to the Philippines and its people'."
• "What is emphasized is not the Eucharistic Congress itself but Manila, the capital of the Philippines, as the seat of that congress."
• "We are of the opinion that the Government should not be embarrassed in its activities simply because of incidental results, more or less religious in character, if the purpose had in view is one which could legitimately be undertaken by appropriate legislation. The main purpose should not be frustrated by its subordination to mere-incidental results not contemplated."
• "Between the exercise of a poor judgment and the unconstitutionality of the step taken, a gap exists which is yet to be filled to justify the court in setting aside the official act assailed as coming within a constitutional inhibition."

• Dimayuga and Fajardo vs. Fernandez (1923), 43 Phil., 304, 307 — Referenced to support the broad application of the writ of prohibition, stating it is granted where necessary for orderly justice administration or to prevent oppressive use of law or multiplicity of actions.
• Bradfield vs. Roberts, 175 U. S., 295; 20 Sup. Ct. Rep., 121; 44 Law. ed., 168 — Cited as precedent for the principle that a government action with a legitimate secular purpose is not rendered unconstitutional merely because it provides an incidental benefit to a religious institution; the primary secular purpose should not be defeated by unintended, secondary religious effects.

• Constitution of the Philippines (1935), Article VI, Section 13, Subsection 3 — This is the "non-establishment" or "no public aid to religion" clause, prohibiting the appropriation or use of public money or property for the benefit of any sect, church, or religious group. It was the central provision petitioner claimed was violated.
• Code of Civil Procedure, Sections 516 and 226 — These sections define the scope of the writ of prohibition in Philippine law, extending it to officers or persons exercising ministerial functions who act without or in excess of jurisdiction. The Court used these to affirm the propriety of the remedy sought.
• Constitution of the Philippines (1935), Article VI, Section 14, Subsection 3 — Mentioned by the Court as an example of a constitutionally permissible concession to religion, specifically the exemption from taxation of properties exclusively devoted to religious purposes.
• Administrative Code, Section 344, par. (c) (Assessment Law) — Cited in conjunction with the constitutional tax exemption for religious properties.
• Constitution of the Philippines (1935), Article XIII, Section 5 — Referenced regarding the constitutional provision allowing optional religious instruction in public schools.
• Administrative Code, Section 928 — Cited in relation to the implementation of optional religious instruction in public schools.
• Administrative Code, Section 29 — Cited to show that certain religious holidays (Holy Week, Thanksgiving, Christmas, Sundays) are recognized as legal holidays, justified by the secular idea that their observance is conducive to beneficial moral results.
• Revised Penal Code, Articles 132 and 133 — Mentioned as examples where certain crimes against religious worship are considered offenses against the fundamental laws of the state, indicating a recognized societal interest in protecting religious peace.
• Act No. 4052 of the Philippine Legislature — This law appropriated funds for the cost of plates and printing of postage stamps with new designs and authorized the Director of Posts to dispose of the appropriated amount "as often as may be deemed advantageous to the Government." The respondent Director of Posts acted under the authority of this Act.