|The Imamate and Its Role in the Exposition of the Divine Sciences|
In the discussion of prophecy it was mentioned that, according to the immutable and necessary law of general guidance, each created species is guided through the path of genesis and generation toward the perfection and felicity of its own kind. The human species is not an exception to this general law. Man must be guided through the very "instinct" of seeking reality and through thought concerning his life in society in such a way that this well-being in this world and the next is guaranteed. In other words, to attain human happiness and perfection, man must accept a series of doctrines and practical duties and base his life upon them.
It has, moreover, already been said that the way to understand that total program for life called religion is not through reason but through revelation and prophecy, which manifests itself in certain pure beings among mankind who are called prophets. It is the prophets who receive from God, through revelation, the knowledge of men's duties and obligations as human beings and who make these known to men, so that by fulfilling them men may attain felicity.
It is evident that in the same way that this reasoning proves the necessity for knowledge to guide men to the attainment of happiness and perfection, it also proves the necessity for the existence of individuals who preserve intact the total body of that knowledge and who instruct the people when necessary. Just as the Divine Compassion necessitates the existence of persons who come to know the duties of mankind through revelation, so also it makes it necessary that these human duties and actions of celestial origin remain forever preserved in the world and as the need arises be presented and explained to mankind. In other words, there must always be individuals who preserve God's religion and expound it when necessary.
The person who bears the duty of guarding and preserving the Divine message after it is revealed and is chosen by God for this function is called the Imam, in the same way that the person who bears the prophetic spirit and has the function of receiving Divine injunctions and laws from God is called the Prophet. It is possible for the imamate and prophecy (nubuwwat) either to be joined in one person or to be separate.
The proof given previously to demonstrate the inerrancy of prophets, also demonstrates the inerrancy of the Imams, for God must preserve His true religion intact and in such a state that it can be propagated among mankind at all times. And this is not possible without inerrancy, without Divine protection against error.
The Difference Between Prophet and Imam
The previous argument about the reception of Divine injunctions and laws by the prophets only proves the basis of prophecy, namely the receiving of Divine injunctions. The argument does not prove the persistence and continuity of prophecy, even though the very fact that these prophetic injunctions have been preserved naturally raises the idea of persistence and continuity. That is why it is not necessary for a prophet (nabi) always to be present among mankind, but the existence of the Imam, who is the guardian of Divine religion, is on the contrary a continuous necessity for human society. Human society can never be without the figure whom Shi'ism calls the Imam whether or not he is recognized and known. God, the Most Exalted, has said in His Book: "So if these disbelieve in it, We have already entrusted it to a people [i.e., the Imams] who do not disbelieve in it" (Quran, VI, 90).
As mentioned above, the functions of prophecy and imamate may be joined in one person who is then appointed to the functions of both prophet and Imam, or to both the reception of the Divine law and its preservation and explanation. And sometimes they can be separated, such as in periods during which there is no prophet living but when there is a true Imam living among men. It is obvious that the number of God's prophets is limited and the prophets have not been present in every period and age.
It is also of significance to not that in God's Book some of the prophets have been introduced as Imams such as the Prophet Abraham, about whom is said, "And (remember) when his Lord tried Abraham with (His) commands, and he fulfilled them, He said: Lo! I have appointed thee a leader [imam] for mankind. (Abraham) said: And of my offspring (will there be leaders)? He said: My covenant includeth not wrongdoers" (Quran, II, 124). And God has also said, "And We made them chiefs [imams] who guide by Our command..." (Quran, XXI, 73).