With reference to the science of jurisprudence and familiarity with the lawful and unlawful issues, it is necessary to take notice of the following point:
As introductory to jurisprudence, the obligations and prohibitions relating to the secondary laws of the religion have been classified into different divisions.
It seems proper to mention these divisions, yet briefly, in order to bring into the light the varieties of obligations and prohibitions and how to comply with them.
An independent obligation is an action that is obligatory in itself, not for accomplishing another action, such as performance of the obligatory prayers and observance of the obligatory fasting.
A dependent obligation is an action that is deemed obligatory in order to accomplish another obligation, such as the minor ablution (wudhu’), the major ablution (ghusl), and the cleansing clothes of impure (najis) things. These obligations are also called introductory obligations.
A devotional obligation is an action that must be performed with the intention of seeking nearness to God and worshipping Him; otherwise, the action is invalid, such as the ritual hajj pilgrimage and the ritual prayers.
An instrumental obligation is an action whose mere performance is sufficiently acceptable, even if seeking nearness to God is not intended, such as cleaning a ceremonially impure object or purifying the body for performing a prayer.
An individual obligation is an act that must be carried out by all individuals independently, such as performing the ritual prayers, the minor ablution, and observing obligatory fasting.
A collective obligation is a particular act that is required from a group; therefore, if it is carried out by any member of the group, the others will be not answerable, such as burying the body of the dead person by one person who has found out about the death.
A determined obligation is an action that is specifically required from every duty-bound person, such as performing the Dawn Prayers.
An optional obligation is when a duty-bound person has to choose to carry out one of two, three, or more actions, such as the right of choosing between performing the Friday prayer or the Midday Prayer or the right of choosing one of three atonements that are made for breaking the fast on a Ramadhan day.
An absolute obligation is an action that does not have any conditions or requirements, such as the obligation to answer a greeting.
A contingent obligation is an action the carrying out of which is contingent upon certain conditions, such as the ritual hajj pilgrimage, which is conditional upon having the means and wherewithal.
A confirmed obligation is an action that is presently required, such as repaying a debt when its due time has arrived.
A pending obligation is an action that is required in the future or after a period, such as repaying a debt within two months or going to Mecca during the hajj season.
A divine obligation is an action that is deemed obligatory by the Holy Qur’an and Sunnah.
A rational obligation is an action that is logically required. For example, if in the law of Islam performing the ritual hajj and ‘umrah is obligatory, the logic of a duty-bound person will see it necessary to prepare the essentials of this journey. Thus, to perform the ritual hajj and ‘umrah is divinely obligatory, while to ready oneself for its journey is rationally obligatory. Theologically, to act kindly towards a kind person, to thank a favor, to refrain from oppression, to stop telling lies—all these and their likes are ordered by reason, whether they are deemed obligatory in the law of Islam or not.
An authoritative obligation is any action that is deemed obligatory through an order issued by a person the obedience to whom is obligatory, such as the Holy Prophet, the Holy Imams, and persons appointed on their behalf, if the order has been independently issued by that person on the strength of such necessary matters like the demands of common interest
A directive obligation is an action that is deemed obligatory because instructs to perform an obligatory matter. For example, if the supreme religious authority orders the recruitment of an army, waging war, or ceasefire, these orders are authoritative obligations. If the leader orders to perform the ritual prayers and fast in Ramadhan, such orders are called directive obligations.
An extended obligation is an action that can be done in an extended period, and the duty-bound person can for example perform it in the beginning, middle, or at the end of its time, such as the Midday Prayers the time of whose performance extends to sunset.
A constricted obligation is an action that must be done in a short or fixed period, such as fasting on each day of Ramadhan, which must be performed from sunrise to sunset and cannot be observed either earlier or later. Another example is the Friday prayer that must be performed at exactly midday in a very limited time.
An urgent obligation is an action that must be performed immediately without delay, such as answering to a form of ritual greeting, performing the ritual Alarm Prayer (salat ayat) immediately after an earthquake, or paying back debts when their due time has arrived and the lender requests for repayment.
Non-urgent obligations are actions the performance of which is not immediately necessary, such as making up for missed prayers or paying back a debt whose owner has not determined a certain time for repayment.
It is forbidden to refrain from carrying out any action that the law of Islam deems obligatory and consequently proscribes abstaining from it. Such an action is a primary obligation, while to refrain from carrying it out is a subordinate prohibition. In this way, every primary obligation necessitates a subordinate prohibition and every primary prohibition necessitates a subordinate obligation. For this reason, subordinate obligations and prohibitions are sometimes mentioned in this book. For example, it was said that drinking wine is forbidden and refraining from it is obligatory, or that defrayment of the zakat tax is obligatory and refraining from defraying it is forbidden. Subordinate prohibitions and obligations are also used in other cases.
If studied carefully, the prohibitions of the religious law can be also classified into most of the divisions of obligations; nevertheless, they are few in kind and rarely mentioned in books of master jurisprudents. Therefore, I have disregarded referring to these divisions.
However, it seems necessary to point out that prohibitions are divided into two main parts, as is understood from the Holy Qur’an and Sunnah:
Logically, sins are not equal in extent; rather, they differ in the levels of intellectual loathing towards them, personal and social immorality, and detestation in the view of God. They are therefore divided into major (kabirah) and minor (saghirah). Inferring this from the traditions of the Holy Infallibles, master scholars have discriminated the major sins from the minor, depending upon the following three points that define the major sins:
1. Sins described as major in traditions (riwayat; reported sayings of the Holy Infallibles).
2. Sins whose committers have been threatened with painful chastisement and casting in Hellfire by the Holy Qur’an and Sunnah. (These are thus major sins)
3. Sins that are considered great by Muslims and religious people.
Thus, any sin falling under one of these three points is a major sin. It naturally follows that any sin, which cannot be placed under any one of these titles, is considered a minor sin. However, this categorization has no practical effect, because in a way, all sins are major, for sinning is transgression against God, violation of the divine boundaries, and stepping over the limits of the obligations and prohibitions. This is in fact enough to consider any sin major.
Although sins have various names, titles, and levels, all of them are violations of justice. If a just person commits a sin, whether major or minor, his/her righteousness will be temporarily lost, until she/he compensates through repentance.