The Categories of Shari' ah Laws
Now we come to the problem that why such and such law of the shari'ah was legislated. Considering the reasons and purposes of the laws, the shari'ah can be divided into four categories:
1. The laws whose reasons and purposes are self evident: For example, helping the needy is highly recommended; killing is forbidden; lying is evil; paying taxes like khums and zakat is obligatory. One does not need any expertise or extraordinary intelligence to know that helping the needy is good, paying taxes is necessary for preserving the financial equilibrium in the society; and that killing and lying is evil.
2. The laws whose reasons and purposes have been explained in the Qur'an and hadith: For example, intoxicants are forbidden, interest is prohibited, fasting in Ramadhan is obligatory and prayers are a must.
The Quran and hadith have said that intoxicant is one of the main causes of evil because an intoxicated person is no longer in control of himself. Although it took the world a long time and a bitter experience to realize the wide-spread harm of drunkenness, Islam declared its harm and evil fourteen centuries ago by saying
“its sin is greater than its profit.” (Surah al-Baqara, 2:219)
Interest is forbidden in Islam. The Qur'an and hadith have explained the harm of interest. Interest leads to destruction of the poor section of the society, and all wealth gravitates towards the already wealthy group.1
Fasting is a physical and spiritual training which brings the servants of Allah (SWT) nearer to Him and makes them more obedient to the shari’ah.
Prayers is a means of expressing our gratitude to Allah (SWT):
“O you who believe! Eat of the good things thatWe have provided you with and thank Allah.” (Surah al-Baqara, 2:172);
it is an important way of achieving peace of mind:
“surely by Allah's remembrance are the hearts set at rest.” (Surah ar-Ra’ad, 13:28);
and it is also a very effective method of making the believer more obedient to the laws of Islam:
“ surely the prayer keeps (one) away from indecency and evil.” (Surah al-Ankaboot, 29:45)
There are many ahadith of our Imams explaining the reasons and purposes of many laws of the shari'ah. Shaykh as-Saduq, the famous Shi'ite scholar, has collected many of these ahadith in his ‘Ilalu ‘sh-Sharaya’.
3. The laws whose reasons and purposes have not been explained in the Qur'an or hadith, but the rising horizon of human knowledge have helped in understanding their purpose and usefulness. For example, why pork is forbidden2 ; why circumcision is highly recommended by the shari'ah, and why only the fish which have scales is permitted in Shi'ah fiqh.
For the benefit of circumcision, we quote Sherman Silber who says that: “There are a number of reasons why circumcision is beneficial and why itought best be performed in infancy. First, it prevents cancer of the penis in later life. Cancer of penis generally occurs when there has been carelessness in taking care of one's foreskin. A second benefit of circumcision is that the wives of circumcised men are less commonly afflicted with cancer of the cervix. The most common benefit of circumcision is that it prevents accumulation of oils and secretions (called smegma) under the foreskin, which lead to infection, swelling, and sometimes contraction of the foreskin so the tip of the penis is trapped inside.3
About the fish, it has been said that the fish that do not have scales are harmful to human beings. Based on that research, American troops in the east were directed that “tropical marine fishes without scales were to be left alone.”
It must be mentioned here that the reasons of the shari'ah laws which have been discovered by human knowledge cannot be regarded as the actual reason (ratio legis) for the legislation of those laws, because the human knowledge is still in its infancy whereas Islam, the final shari' ah of Allah (SWT), is to stay in practise up to the end of this world. However, the scientific facts can be used to explain the usefulness and benefits of the shari'ah laws.
4. The laws whose reasons and purposes have neither been explained in the Qur'an and hadith, nor the new advancement in human knowledge has been able to explain them: For example, why four rak'ats (cycles) in noon, afternoon and night prayers while only three in evening and two in subh prayers.