1) Philippine framework: what a “contract” is and why the requisites matter

Under the Civil Code, a contract is essentially a meeting of minds between two persons whereby one binds himself, with respect to the other, to give something or to render some service (Civil Code, Art. 1305). Philippine contract law is anchored on several core principles that shape how courts evaluate consent, object, cause, and validity:

Autonomy of contracts: parties may establish stipulations, clauses, terms, and conditions as they deem convenient, so long as they are not contrary to law, morals, good customs, public order, or public policy (Art. 1306).
Mutuality: validity and compliance cannot be left to the will of only one party (Art. 1308).
Obligatory force and good faith: obligations arising from contracts have the force of law between the parties and must be complied with in good faith (Art. 1159).
Relativity: contracts take effect only between the parties, their assigns, and heirs, subject to exceptions like stipulation pour autrui and real rights (Art. 1311).

Against that backdrop, the Civil Code states the essential requisites of contracts:

Consent of the contracting parties;
Object certain which is the subject matter of the contract; and
Cause of the obligation established (Art. 1318).

A failure or defect in any of these requisites is typically what determines whether a contract is valid, voidable, unenforceable, rescissible, or void/inexistent.

2) Consent: the “meeting of minds”

A. What consent means in Philippine law

Consent is manifested by the meeting of the offer and the acceptance upon the thing and the cause that are to constitute the contract (Art. 1319). It is not enough that parties talked or had a general intention; the law looks for concurrence on:

the subject (what is being given/done), and
the cause (the juridical reason/consideration in Civil Law sense, discussed below).

B. Offer and acceptance: how contracts are perfected

Offer must be certain (definite enough that the other party can accept it as is) (Art. 1319).
Acceptance must be absolute. A qualified acceptance is a counter-offer (Art. 1319).
If the offeror fixes time, place, or manner of acceptance, the offeree must comply (Art. 1321).
Offer may become ineffective upon death, civil interdiction, insanity, or insolvency of either party before acceptance is conveyed (Art. 1322).
Business advertisements are generally invitations to make an offer, not definite offers (Art. 1325).
Advertisements for bidders are invitations to make proposals; the advertiser is not bound to accept the highest or lowest bid unless the contrary appears (Art. 1326).

Acceptance by letter/telegram (and by practical extension, analogous communications): acceptance does not bind the offeror except from the time it comes to the offeror’s knowledge, and the contract is presumed entered into at the place where the offer was made (Art. 1319).

C. Capacity to give consent (and why it matters)

The Civil Code identifies those who cannot give valid consent, including unemancipated minors, insane or demented persons, and deaf-mutes who do not know how to write (Art. 1327). Capacity is generally presumed, and the burden of proving incapacity lies on the person alleging it (Art. 1329).

Modern Philippine context note: the statutory age of majority has been reduced to 18, which affects who is treated as a minor for capacity purposes. Even when a person is of age, capacity issues can still arise from guardianship, mental incapacity, or other legally recognized limitations.

Effect of lack of capacity: contracts where one party cannot give valid consent are typically voidable, not automatically void, unless another ground renders the contract void/inexistent (see validity classifications).

D. Consent must be “intelligent, free, spontaneous, and real”: vices of consent

A contract where consent is given through mistake, violence, intimidation, undue influence, or fraud is voidable (Art. 1330, Art. 1390).

1) Mistake (error)

Mistake vitiates consent when it refers to:

the substance of the thing,
conditions that principally moved the parties, or
identity/qualifications of a person when it is the principal cause, and it is substantial—not trivial. Mistakes of accounting or calculation typically do not annul but may be corrected, depending on circumstances. The Civil Code’s error provisions are detailed in Arts. 1331–1334.

2) Violence and intimidation

Violence involves physical force to compel consent.
Intimidation exists when one party is compelled by a reasonable and well-grounded fear of an imminent and grave evil upon his person or property (or those of certain close relations), considering the party’s age, sex, and condition (Art. 1335).

3) Undue influence

Undue influence occurs when a person takes improper advantage of another’s power over the will of the latter, depriving him of reasonable freedom of choice (Art. 1337).

4) Fraud (dolo)

Fraud is present when, through insidious words or machinations, one party induces the other to enter into a contract which the other would not have entered into otherwise (Art. 1338). The Code distinguishes:

Causal fraud (serious, determining) → makes the contract voidable;
Incidental fraud → does not annul the contract but may give rise to damages (Art. 1344).

The Code also clarifies limits: ordinary “trade puffery” is not necessarily fraud (Art. 1340), and mere expression of opinion generally is not fraud unless special circumstances exist (Art. 1341).

E. Consent through representatives: authority, agency, and unauthorized contracts

Consent may be given through a lawful representative (e.g., guardian, agent). Problems arise when someone purports to bind another without authority or beyond authority:

Such contracts can fall under unenforceable contracts (unauthorized contracts) unless properly ratified (Art. 1403(1)).
Ratification can cure certain defects (notably in unenforceable and voidable contracts), but cannot validate what the law declares void/inexistent.

F. Consent in standard-form and modern transactions

Philippine practice commonly involves contracts of adhesion (take-it-or-leave-it forms). These are not invalid per se, but ambiguous provisions tend to be construed against the drafter, and courts scrutinize unfairness, lack of real assent, or unconscionable terms under broader doctrines (good faith, public policy, equitable considerations).

Electronic contracting is generally compatible with consent principles so long as there is a reliable way to show offer, acceptance, and assent (including the use of electronic signatures under special laws), but the Civil Code’s core requirement remains: a provable meeting of minds.

3) Object: what the contract is “about”

The object is the prestation—the thing, right, or service that is the subject matter of the contract. The Civil Code requires that it be:

A. Within commerce, lawful, and not contrary to public policy

All things which are not outside the commerce of men may be the object; all rights which are not intransmissible may also be the object, provided the contract is not contrary to law, morals, good customs, public order, or public policy (Art. 1347).

A key limitation: no contract may be entered into upon future inheritance, except in cases expressly authorized by law (Art. 1347). This prevents dealing in mere expectancies of inheritance, with narrow statutory exceptions.

B. Possible (physically and legally)

Impossible things or services cannot be the object (Art. 1348). “Impossible” may be:

physical (cannot be done), or
legal (prohibited by law).

C. Determinate or determinable

The object must be determinate as to its kind, or at least determinable without needing a new agreement (Art. 1349). Examples:

“One of my cars” (without any method of determination) is problematic.
“One of my cars, to be chosen by the buyer from the list attached” is determinable.

D. Services as object

Contracts for services must still satisfy law and public policy. Certain services may be void if they involve illegal acts, violate labor standards, offend morals, or are otherwise prohibited.

E. Partial illegality and separability

If a contract has multiple prestations, and one is illegal while the others are legal, courts may examine whether the illegal part is separable from the legal parts. If inseparable and the illegality affects the cause/object in a way that taints the whole agreement, the entire contract may be void.

4) Cause: the juridical reason for the obligation (not the same as motive)

A. What “cause” means in Philippine Civil Law

Cause is the essential reason why each party binds himself. The Civil Code defines it by type of contract (Art. 1350):

Onerous contracts: the cause for each party is the prestation or promise of the other. Example: In a sale, the seller’s cause is the buyer’s payment; the buyer’s cause is the seller’s delivery of the thing sold.
Remuneratory contracts: cause is the service or benefit remunerated.
Gratuitous contracts: cause is the liberality of the benefactor.

B. Cause vs. motive

The Code expressly distinguishes cause from motive: the particular motives of the parties are different from the cause (Art. 1351).

Cause is objective and part of the contract’s juridical structure.
Motive is personal and generally irrelevant to validity—unless the motive is made a condition, is shared and principal, or the contract is structured to pursue an illegal purpose such that it becomes part of cause/object analysis.

C. Presumption of cause and its legality

A contract without cause, or with unlawful cause, produces no effect (Art. 1352).
A false cause renders the contract void if there is no proof that it is founded upon another true and lawful cause (Art. 1353).
Even if the cause is not stated, it is presumed to exist and to be lawful, unless the debtor proves the contrary (Art. 1354).

D. Inadequacy of cause (lesion) as a rule

As a general rule, lesion or inadequacy of cause does not invalidate a contract (Art. 1355). Philippine law generally respects freedom of contract—even “bad bargains”—subject to important exceptions:

rescissible contracts for lesion in specific relationships (e.g., guardianship/representation),
fraud, undue influence, or other vices,
unconscionability doctrines in jurisprudence and equity,
public policy limitations.

5) Validity and effectiveness: how Philippine law classifies defective contracts

“Validity” in Philippine law is best understood by distinguishing:

existence/perfection (did a contract come into being?),
validity (is it legally sound?), and
enforceability (can it be sued upon as is?).

A contract is generally perfected by mere consent (Art. 1315), but some contracts require more for perfection or validity:

Real contracts (e.g., commodatum, deposit, pledge) are perfected by delivery.
Formal contracts require compliance with a form for validity (e.g., donations of immovables) under special provisions.

The Civil Code groups defective contracts into four major classes:

A. Rescissible contracts (valid but subject to rescission)

Rescissible contracts are valid and binding but may be rescinded because they cause economic damage or prejudice in situations protected by law (Arts. 1380–1389). Typical grounds include:

contracts entered into by guardians/representatives where the ward suffers lesion beyond a threshold,
contracts in fraud of creditors (accion pauliana),
contracts involving things under litigation entered into without required knowledge/authority.

Key characteristics:

Rescission is generally a subsidiary remedy: it is available only when there is no other legal means to obtain reparation.
It usually requires mutual restitution to restore parties, subject to legal nuances.
The action is subject to a prescriptive period (commonly four years, depending on the case; Art. 1389).

B. Voidable contracts (valid until annulled)

Voidable contracts are those where consent is defective or capacity is lacking (Art. 1390), specifically:

where one party is incapable of giving consent, or
where consent is vitiated by mistake, violence, intimidation, undue influence, or fraud.

Key characteristics:

Binding unless annulled by a proper action.
Susceptible to ratification, which cleanses the defect retroactively (Arts. 1392–1396).
Annulment actions generally prescribe in four years, with the starting point depending on the ground (e.g., from discovery of fraud or cessation of intimidation) (Art. 1391).

C. Unenforceable contracts (cannot be sued upon unless ratified or properly evidenced)

Unenforceable contracts are those that cannot be enforced by action unless ratified or unless legal requirements are met (Art. 1403), including:

Unauthorized contracts entered into in the name of another without authority (or beyond authority) (Art. 1403(1)).
Those that do not comply with the Statute of Frauds (Art. 1403(2)).
Those where both parties are incapable of giving consent (Art. 1403(3)).

Statute of Frauds (writing requirement for enforceability)

Certain agreements must be in writing (or at least some note/memorandum) to be enforceable, such as:

agreements not to be performed within a year,
special promise to answer for another’s debt,
agreements in consideration of marriage (other than mutual promise to marry),
sale of goods above a statutory amount,
sale of real property or an interest therein,
representation as to the credit of a third person.

Important limits:

The Statute of Frauds generally applies to executory contracts; once a contract is partially or fully performed, the bar often cannot be invoked to defeat it.
It affects enforceability, not necessarily existence.

D. Void or inexistent contracts (produce no legal effect)

Void/inexistent contracts are those that produce no effect and cannot be ratified. Grounds include those enumerated in Art. 1409, such as:

cause/object/purpose contrary to law, morals, good customs, public order, or public policy,
absolutely simulated or fictitious contracts,
those whose cause or object did not exist at the time of transaction,
those whose object is outside commerce,
those contemplating an impossible service,
those where the intention cannot be ascertained,
those expressly prohibited or declared void by law.

Key characteristics:

They generally cannot be cured by ratification.
An action or defense to declare inexistence does not prescribe (Art. 1410), subject to nuanced applications and equitable doctrines in specific contexts.
Illegality triggers rules like in pari delicto (both at fault), with recognized exceptions in the Civil Code’s provisions on illegal contracts (Arts. 1411–1422).

6) Form and solemnities: when form affects validity vs enforceability

A. General rule: no special form required

Contracts are generally obligatory in whatever form they are entered into, provided all essential requisites are present (Art. 1356). However, the law may require a specific form:

for validity (solemn contracts), or
for enforceability (Statute of Frauds), or
for convenience/greater efficacy (e.g., to bind third persons through registration, to meet evidentiary needs).

B. Public instruments and notarization

Certain contracts must appear in a public document (public instrument) for specified legal purposes—particularly those affecting real rights over immovable property—under Art. 1358, and related property and registration laws. Notarization and registration often matter to:

bind third persons,
enable registration in the Registry of Deeds,
strengthen proof of due execution.

Failure to follow these may not always void the contract between the parties, but it can affect enforceability, admissibility, and third-party effects.

7) Putting it together: a structured validity analysis (Philippine method)

A practical Civil Code–based analysis usually proceeds in this order:

Is there consent?
- Was there a definite offer and absolute acceptance? (Art. 1319)
- Did a party lack capacity? (Arts. 1327, 1329)
- Was consent vitiated by mistake, violence, intimidation, undue influence, or fraud? (Art. 1330)
- Was the person who “consented” authorized to bind the principal? (Art. 1403(1))
Is the object valid?
- Within commerce and lawful? (Art. 1347)
- Possible? (Art. 1348)
- Determinate/determinable? (Art. 1349)
- Not a prohibited future inheritance? (Art. 1347)
Is there a lawful cause?
- Proper cause by contract type? (Art. 1350)
- Not unlawful or absent? (Art. 1352)
- Not merely false without proof of a true lawful cause? (Art. 1353)
- Presumed lawful unless disproved? (Art. 1354)
Does the law require a form for validity or enforceability?
- Statute of Frauds issues? (Art. 1403(2))
- Special formalities (donations, real rights, registration-sensitive acts)?
If defective, what is the classification and consequence?
- Rescissible (valid but rescindible)
- Voidable (annullable; can be ratified)
- Unenforceable (not actionable unless ratified/evidenced)
- Void/inexistent (no effect; not ratifiable)

8) Core takeaways

Consent, object, and cause are the Civil Code’s essential requisites (Art. 1318).
Consent requires a true meeting of minds and can be defeated by incapacity or vices like fraud and intimidation (Arts. 1327, 1330).
Object must be lawful, possible, and determinate/determinable, and must not be outside commerce or prohibited (including prohibited dealings in future inheritance) (Arts. 1347–1349).
Cause is the juridical reason for the obligation, distinct from motive; it must exist and be lawful (Arts. 1350–1355).
Defects lead to different consequences depending on whether the contract is rescissible, voidable, unenforceable, or void/inexistent (Arts. 1380–1389; 1390–1402; 1403–1408; 1409–1422).