Here’s a comprehensive and detailed breakdown of the topic "Effect and Application of Laws" under Civil Law > I. Preliminary Title in the Philippine legal system:

1. Legal Basis: Civil Code of the Philippines (Republic Act No. 386)

The Civil Code of the Philippines contains provisions about the effect and application of laws under its Preliminary Title, specifically in Articles 1 to 18. This section sets the fundamental principles governing how laws are enacted, applied, interpreted, and enforced in the Philippines.

2. Key Articles and Their Interpretation

Article 1: Effectivity of Laws

Laws take effect 15 days after publication in the Official Gazette or a newspaper of general circulation, unless specified otherwise.
Purpose: To provide the public with ample notice and opportunity to be informed about new laws.
Doctrine of Constructive Notice: Citizens are presumed to know the law once it is published, removing ignorance as an excuse for non-compliance.

Article 2: Publication Requirement

This article emphasizes that laws must be published as a prerequisite for enforceability, underscoring the importance of transparency and accessibility in legislation.
Case Law: In Tañada v. Tuvera (1986), the Supreme Court held that publication in the Official Gazette or a newspaper of general circulation is indispensable for laws to be effective.

Article 3: Ignorance of the Law Excuses No One (Ignorantia Legis Neminem Excusat)

No one can escape liability by claiming ignorance of the law.
Rationale: This principle ensures uniform application and obligates all citizens to familiarize themselves with existing laws.

Article 4: Laws Should Have Prospective Effect Unless Otherwise Stated

General Rule: Laws apply only to acts or events that occur after their effectivity.
Exception: Retroactive application is permitted if expressly stated or when the law is favorable to the accused (in criminal cases).
Case Law: In Pepsi-Cola Bottling Co. v. Secretary of Labor, the Supreme Court reiterated that laws are generally not retroactive.

Article 5: Waiver of Rights

Rights established by law may be waived, provided it is not against public policy, morals, or detrimental to a third person.
Exceptions: Rights inalienable or necessary for personal development and dignity cannot be waived (e.g., human rights).

Article 6: Effectiveness of Waivers or Renunciations

Waivers must be clear, voluntary, and unequivocal, with an understanding of what rights are being waived.
Legal Limitation: Certain rights protected by law (like labor rights) may not be waived if such waiver contravenes the law.

Article 7: Repeal of Laws

Laws may be repealed by express repeal (stating explicitly that a prior law is repealed) or implied repeal (new law contradicts prior law without explicitly stating repeal).
Doctrine of Implied Repeal: Only occurs when there is an irreconcilable conflict between two laws.

Article 8: Judicial Decisions

Jurisprudence or Case Law: The Supreme Court’s decisions form part of the legal system and act as judicial precedents.
Stare Decisis Principle: Lower courts are bound by Supreme Court decisions to ensure consistency and stability in law.

Article 9: No Judge or Court Shall Decline to Render Judgment Due to Ambiguity or Silence in Law

Courts must render judgment even if the law is silent or unclear, using principles of equity, justice, and natural law to fill the gap.

Article 10: Gap-filling via Custom, Justice, and Equity

Custom: Long-established practices can serve as law if recognized by the courts and aligned with justice.
Justice and Equity: Courts must interpret and apply laws in a fair manner, adhering to justice and equity principles.

Article 11: Custom Supplementing the Law

Custom may apply when statutes are silent on an issue, provided it does not violate legal principles.
Custom Requisites: Must be well-established, practiced by the majority, and conform to law.

Article 12: Application of Foreign Law, Judgment, or Contract

Lex Loci Principle: Foreign laws may apply in the Philippines if recognized by domestic law and international comity.
Conflict of Law: Courts may enforce foreign judgments if they are consistent with public policy and local interests.

Article 13: Computation of Legal Periods

Calendar Days: Unless stated otherwise, the computation of time under Philippine law follows a calendar day basis.
Exclusions in Computation: Specific instructions (like excluding weekends or holidays) apply in certain laws or rules.

Article 14: Retroactivity of Penal Laws Favorable to Accused

Penal laws favorable to the accused can be retroactive unless they explicitly state otherwise.
Purpose: To align criminal penalties with the reformatory and equitable goals of criminal justice.

Article 15: Laws Govern Nationals Wherever They Are

Nationality Principle: Philippine citizens are generally subject to Philippine law even if they reside or act abroad (for matters related to status, family rights, and obligations).

Article 16: Property and Succession

Lex Rei Sitae Principle**: Property laws apply based on the property’s location.
Succession Law: Governed by the national law of the deceased, addressing family unity and inheritance rights.

Article 17: Forms and Formalities of Acts and Contracts

Lex Loci Celebrationis: The form of public documents follows the law of the place where they are executed.
Exceptions: If Philippine law requires a specific form for validity, that form is generally required.

Article 18: Meaning and Interpretation of Words and Phrases

The spirit of the law is prioritized over the literal text, especially when the letter would lead to injustice.
Interpretation Rules: When ambiguous, words and phrases are interpreted in the way they were intended by the legislature, often based on judicial or doctrinal interpretation.

3. Application and Enforcement

Public Policy and Morality: The courts balance statutory requirements with prevailing moral standards and public welfare considerations.
Judicial Discretion and Equity: When interpreting or applying laws, the judiciary may use principles of justice and equity, ensuring laws achieve their intended purpose and do not result in absurd outcomes.
Judicial Review: Courts, particularly the Supreme Court, hold the authority to review laws for constitutional conformity, upholding or nullifying them accordingly.

4. Special Considerations and Doctrinal Principles

Hierarchy of Laws: In cases of conflict, the Constitution prevails, followed by statutes, administrative regulations, and customary norms.
Administrative Interpretation: Courts may consider administrative interpretations of laws, especially when technical expertise is involved.

5. Conclusion

The Preliminary Title of the Civil Code on the effect and application of laws in the Philippines underscores fundamental principles of legal effectivity, accessibility, and procedural justice. These principles aim to ensure a clear, fair, and predictable legal framework that balances statutory mandates with flexibility in interpretation.