The conceptual foundation of obligation traces as far back to ancient Roman law which defines obligation as a means of an undertaking or legally binding relationships where one party promises the other party to perform some acts or to do something. Ancient well-known Roman lawyers defined obligations based on their personal opinion, which as a result has developed the concept of obligation.

Year Gay, a Roman jurist, defines obligation as ‘a means of personal claim brought against another in order to force him before us to give us so as to we are able to enforce our rights. Gay also classifies obligation in terms of contract, quasi-contract, delict, and quasi-delcit

Pavel year also understood obligation as an undertaking not by Roman citizens to perform some acts or to do or to give or to render rights to non-roman citizens regarding to give, to do, or to render some rights to roman citizens.

The concept of obligation by both classical legal scholars was unilateral in character and discriminatory in nature since it imposes obligation to do, to give or to render rights only on non-roman citizens not the Romans.

However, the institute of Justinian defines obligation as a legally binding relations when Roman citizens undertake to perform certain acts or to do something in accordance with the Roman law.

Obligation defined in the institute of Justinian, differed from the obligations defined in the classical Roman jurists in that the institute defines obligation in the aspect that Roman citizens to carry out.

In general the concept of obligation can clearly be expressed as;

a)      Obligation to give or not to give

b)      Obligation to do or not to do

c)      Obligation to render rights to others to do something.

Definition of Obligations

Black’s law dictionary defines obligation as ‘a legal duty or moral duty to do or not to do something’.  Common-law scholars such as Fredrick Pollock defines obligation in its popular sense as merely synonym for ‘duty’. In its legal sense derived from roman laws ‘an obligation is the bond of legal necessity or vinculum juris which binds together two or more determinate individuals’.

John Salmond (year) defined obligation in its more general acceptation as ‘something the law or morals command a person to do a command that is made effective by the imposition of sanction if a person failed to comply such a command’

In the modern legal systems and currently existing legal materials, there is no exact or single whole definition of obligation. However, some scholars define it based on their own legal system For instance French judges define the term obligation as a legally binding relations to another party is obliged to give or to do or not to do something.

Likewise the Ethiopian civil code, in the book IV of the code uses the term obligations without defining what it means.  However, like French judges who define obligations indirectly from article 1101 of the French civil code of the term contract as an agreement whereby two or more persons as between themselves create, vary or extinguish obligations of proprietary nature.

Sources of obligations

According to Gay, Roman jurist, the fundamental source of obligation can be classified into two:

a) Contract

b) Beyond the contract

Those obligations, which arises beyond the contract, are divided into unjust enrichment (quasi-contract), unlawful acts (delict) and causing physical injure to the person or causing damage to property of person (quasi-delict).

In modern time, the laws of different countries clearly express the sources of obligation. For instance, French civil code classifies the source of obligation as;

i)   Obligation that arises from contract

ii)  Obligations that arise beyond the contract

iii) Obligation that arises from the unlawful acts

iv) Obligations that arises from the causing of physical injure or causing material damage

vi) Obligations arising from law

In Ethiopian legal system, there are no clearly stated classifications of sources of obligations. But Art.1675 of Ethiopian civil code generally expresses obligations as arising from contractual agreements.

However, the close readings of the provisions of the civil code show that there are other sources of obligations-like those arising from non-contractual relationships (from Art.2027-2178), obligations arising from unlawful acts or obligation that arises from the causing of physical injure or obligation arising from the causing of material damage (fromArt.2027-2161) and finally, obligations arising from unjust enrichment (from Art.2162-2178).

In so far as an obligation arising from the law is concerned, it happens in situations when law imposes obligations on persons to give or not to give, to do or not to do some acts recognized in almost all-legal systems.

Obligation arising from the law is a unilateral obligation imposed on citizens or contracting parties without their consent. It includes among other things

• Obligation to pay income taxes
• Obligation to render military services
• Obligations of creditors
• Obligation of debtors
• Obligations of families to their children, etc.

Types of Obligations

Obligations can be classified based on the nature of activities, and the number of parties legally bound by the obligation. Accordingly, they can be classified into:

1) Divisible obligation

This is one whereby a party undertakes to perform its obligations by dividing into parties. For instance, if A and B owed C 1,000 BIRR such parties to the obligation perform or discharge the obligations by paying half (part) of the debt to C, which is 500 each.

2) Indivisible obligations

In this type of obligation, the performance of the obligation undertaken cannot be divided into parts. Hence, in this type of obligation partial performance is impossible given the conditions and circumstances of its formation, which does not allow the performance of obligation by dividing into parts.

3) Positive obligation

This is a situation where a person’s obligation is to do or to give some thing to another. It requires an action from the debtor.

4) Negative obligation.

This is a situation where a person’s obligation does not to do some thing or it refrains from doing some thing.  Such obligations are also called obligations not to do.

Example, company A may agree with company B in which company A under takes an bligation not to produce or sell certain goods in the same market.

Based on the number of parties legally bound, obligations can be classified into unilateral, bilateral, and multilateral obligations.

a) Unilateral obligation arises from contract in which two parties are participate. However, only one of the parties is legally bound by the contract for the benefit of the other contracting party.  Example, donations

b) Bilateral obligation arises from a contract entered into by two parties in which these contracting parties are bound legally to each other on equal terms. Accordingly, there are two promisors and two promises.

c) Multilateral obligation. This is a case where more than two persons undertake to perform an obligation. Such obligations can be classified into three:

1) Simple joint obligation

2) Joint obligations

3) Several and joint obligations

1) Simple joint obligation

In this type’s obligation, parties who are bound by such obligation are not jointly liable for the total debts, but each debtor is liable for its own share with the exception of Art.1917 of the Ethiopian civil code

2) Joint obligations

It arises from the contractual obligation in which more than two parties participate and debtors are jointly liable for the debt secured as a result of the obligation entered into with the creditor or creditors.

3) Several and joint obligations

In this kinds obligations the co-debtors shall be jointly and severally liable unlike joint obligation where the debtors are jointly obliged to undertake a given obligation, in the several and joint obligation, the creditor may require all the debtors or one of them to discharge the obligation in whole or in part.