Fiqh tibbi has evolved through three distinct stages each being characterized by a dominant mode of ijtihad.
In the initial period (0 – 1370 H) fiqh tibbi was derived directly from the two primary sources of the Law
(Qur’an and sunnat). This was possible because the technological and social landscape did not change drastically
from the situation during the prophetic era. An example was the determination by Ali Ibn Abi Talib that the minimum period
of gestation was 6 months based on reading two verses of the Qur’an one stating that the period of pregnancy and breast-feeding
was 30 months and the second one stating that the period of breast-feeding is 2 years i.e. 24 months.
In the middle period (1370 – 1420 H) drastic technological and social changes necessitated derivation of
fiqh tibbi from secondary sources: (a) the 2 transmitted ones, masaadir naqliyyat of analogy, qiyaas,
and scholarly consensus, ijma, and (b) the logical ones, masaadir ‘aqliyyat, that are istishaab,
istihsaan, and istirsaal. Qiyaas was used most extensively for example (i) solid organ transplantation was analogous
to permission to eat the flesh of a dead human in conditions of necessity, dharuurat; (ii) sale of milk by a wet nurse
was analogous to sale of organs for transplantation and blood for transfusion; (iii) use of modern contraceptive technology
was analogous to coitus interruptus, ‘azal. Towards the end of the second period, further developments
in medical technology strained qiyaas with the result that its analysis and conclusions were no longer robust or even
reliable. For example surrogate motherhood was rejected although on biological grounds it could be analogous to foster motherhood.
The cause of this is that modern problems are drastically different in nature and context to be analogous
The difficulties in the use
of qiyaas can be overcome in the modern period of fiqh tibbi (1420 H onwards) by using the theory of purposes
of the Law, maqasid al shari’at, to derive robust and consistent legal rulings. Maqasid al shari’at
are not a new theory; they have been around but there was no serious need to invoke them. By the 6th century H
work on the closed part of the Law had been completed with no more developments expected. Jurists turned their attention the
open part of the Law under which maqasid are considered. According to this theory Medical intervention is supposed
to achieve 5 purposes: diin, health, progeny, intellect, and wealth. These 5 purposes must be protected, preserved,
and promoted. There are situations in which the purposes may conflict for example pursuing the health of a terminally ill
patient in the intensive care unit is so expensive that it violates the purpose of preserving wealth. Such conflicts can be
resolved by use of the 5 principles of the Law, qawa’id al shari’at.