Profession of Unity

It has been related that when al-Ma'mun (the cruel and cunning Abbasid caliph) desired to install Emam Reza (A.S) (as his successor), he collected together Banu Abbas and said to them, "Verily I desire to install Emam Reza (A.S.) in this affair after me".
Banu Abbas envied Emam Reza (A.S.) and said.
Thou appointest an ignorant man who possesses not the insight to direct the caliphate. Therefore send for him. He will come to us and thou wilt see how his ignorance decides thee against him." So he sent for him and he came, Banu Abbas said to him,
O Abu-l-Hasan! Ascend the pulpit and display for us a sigh whereby we may worship God."
So he ascended the pulpit and sat for a long time, his head bowed in silence. Then he trembled a great trembling and stood up straight, praised and lauded God, and asked His blessing for His prophet(S.A.W.) and his holy household(A.S). Then he said, "The first element in the worship of God is knowledge of Him, the root (asl) of knowledge of Him is to profess His Unity (tawhid), and the correct way (nizam) to profess the Unity of God is to negate attributes from Him. For the powers of reason testify that every attribute and everything possessing an attribute (mawsuf) is created. Everything possessing an attribute testifies that it has a creator which is neither attribute nor possesses an attribute. Every attribute and everything possessing an attribute testify to connection (iqtiran, between the attribute and that to which it is attributed). Connection testifies to temporality (hadath). And temporality testifies that it accepts not the Beginningless, which accepts not the temporal.
"So it is not God whose Essence is known through comparison. It is not His Unity that is professed by someone who attempts to fathom Him. It is not His reality (haqiqah) that is attained by someone who strikes a similitude for Him. It is not He who is confirmed (tasdiq) by him who professes an end for Him. It is not He to whom repairs he who points to Him. It is not He who is meant by him who compares Him (to something). It is not to Him that he who divides Him into parts humbles himself. And it is not He who is desired by him who conceives of Him in his imagination.
"Everything that can be known in itself (bi-nafsihi) is fashioned (masnu). All that stands apart from Him is an effect (malul). God is inferred from what He fashions , the knowledge of Him is made fast by the powers of reason, and the argument (hujjah) for Him is established by (man's) primordial nature (al-fitrah).
"God's creating of the creatures is a veil between Him and them. His separation (mubayanah) from them is that He is disengaged from their localization (ayniyyah). That He is their origin (ibtida) is proof for them that HE has no origin, for none that has an origin can originate others. That He has created them possessing means (of accomplishing things) is proof that He has no means (adah), for means are winess to the poverty of those who use them.
"So His names are an expression (tabir), His acts (afal) are (a way) to make (Him) understood (tafhim), and His Essence is Reality (haqiqah). His inmost center (kunh) separates (tafriq) Him from creation, and His otherness (ghuyur) limits (tahdid) what is other than He. Therefore ignorant of God is he who asks for Him to be described! Transgressing against Him is he who seeks to encompass Him! Mistaken is he who imagines to have fathomed Him!
"Whoso says "how?" has compared Him (to something). Whoso says "why?" has professed for Him a cause (talil). Whoso says "when?" has determined Him in time (tawqit). Whoso says "in what?" has enclosed Him (tadmin). Whoso says "to what?" has professed for Him a limit (tanhiyah). Whoso gives Him an end has associated an end with Him. Whoso associates an end with Him has divided Him. Whoso divides Him has described Him. Whoso describes Him has deviated from the straight path (ilhad) concerning Him.
"God does not change with the changes undergone by creation, just as He does not become limited by delimiting (tahdid) that which is limited (al-mahdud). He is One (ahad), not according to the explantion offered by number (ta'wil adad); Outward, not according to the explanation of being immediate (to the senses); Manifest, not through the appearance of a vision (of Him); Inward (batin), not through separation (muzayalah); Apart (mubain), not through distance; Near, not through approach; Subtle, not through corporealization; Existent, not after non-existence; Active, not through coercion; Determining, not through the activity of thought (jawl fikrah); Directing (mudabbir), not through movement; Desiring, not through resolution; Willing (sha), not through directing attention (himmah), Grasping (mudrik), not through touch (majassah); Hearing, not through means: and Seeing, not through organs.
"Times accompany Him not, places enclose Him not, slumber seizes Him not, attributes delimit Him not, and instruments (adawat) are of no use to Him. His being (kawn) precedes times (al-awqat), His existence (wujud) non-existence and His beginning-lessness (azal) beginning (al-ibtida).
"By His giving sense to the sense organs it is known that He has no sense organs. By His giving substance to substances it is known that He has no substance. By His causing opposition among things it is known that He has no opposite. By His causing affiliation among affairs it is known that He has no affiliate. He opposed darkness to light, obscurity to clarity, moisture to solidity, and heat to cold. He joins together those things which are hostile to one another and separates those which are near. They prove (the existence of) their Separator by their separation and their Joiner by their junction. That is (the meaning of) His words - He is the Mighty and Majestic - 'And of everything created We two kinds: haply you will remember' (LI, 49).
"So through them He sepatated 'before' and 'after' that it might be known that He has no before and after. They testify with their temperaments that He who gave them temperaments has no temperament. They prove by their disparity (tafawut) that He who made them disparate has no disparity. They announce through their subjection to time that He who subjected them to time is not subject to it Himself.
"He veiled some of them from others so that it might be known that there is no veil between Him and them other than them. His is the meaning lordship(al-rububiyyah) when there was none over whom He was Lord, the reality of godhood (al-ilahiyyah) when there was nothing for whom He was God, the meaning of Knower when there was nothing to be known, the meaning of Creator (khaliq) when there was nothing created (makhluq) and the import of hearing when there was nothing to be heard. It is not because He created that He deserves the meaning (of the term) 'Creator' and not because He brought the creatures into being that the meaning of 'making' is derived.
"How (should it not be so)? For mudh ('ever since') conceals Him not, qad ('already') brings Him not near, la'ala ('perhaps') veils Him not, mata ('when?') limits Him not in time, hin ('at the time of ') contains Him not, and ma ('with?') brings Him not into association. Instruments (adawat) limit only themselves and means (alah) allude only unto their own like. Their activities are found only in things. Mudh withholds things from being eternal (qidmah), qad shields them from beginninglessness, and law la ('if only') wards off perfection (al-takmilah). Things become separate and prove (the existence of) their Separator. They become distinguished and prove their Distinguisher (mubain). Through them their Maker manifests Himself to the powers of reason. Through (these powers) He becomes veiled to sight, to them imaginations appeal for a decision, in them is substantiated (only) other than Him, from them is suspended the proof and through them He makes known to them the acknowledgement (al-iqrar).
"Confirmation (tasdiq) of God is made fast by the powers of reason, and faith (iman) in Him reaches perfection through acknowledgment. There is no religiosity (diyanah) except after knowlege (marifah), no knowlege except through sincerity (ikhlas) and no sincerity along with comparison. There is no negation (nafy) of comparison if there is affirmation (ithbat) of attributes.
"So nothing in creation is found in its Creator. All that is possible in it is impossible in its Maker. Movment (harakah) and stillness (sukun) do not affect Him. How should that which He effect (in others) have effect upon Him, or that which He has originated recur for Him? Then His Essence would be disparate, His inmost center divided, His signification (mana) prevented from eternity. How would the Creator have a meaning different from the created?
"If something from behind limited Him, then something in front would limit Him. If perfection (tamam) were seeking Him, imperfection would be upon Him. How should that which does not transcend (imtina) temporality be worthy of (the Name) 'Beginningless'? How should that which does not transcend being produced (insha) produce the things (of the world)? There then would have arisen in Him a sign of having been made (al-masnu) and He would become a proof (dalil) after having been the proven (madlul alayh).
"There is no argument in absurd opinions (such as the above), no answer when it (absurdity) is asked about, no glorification of Him in its meaning. Nor is there any ill in distinguishing Him from creation, unless it be that the Eternal accepts not to be made two, nor the Beginningless to have a beginning.
"There is no god but God, the All- high, the Tremendous. They have cried lies who ascribe equals to God! They have gone astray into far error and suffered a manifest loss! And God bless Muhammad(S.A.W) and his household(A.S), the pure."

The Veil
It was related from Muhammad ibn 'Abdallah al-Khurasani, the servant of Emam Reza (A.S.) that a man from among the unbelievers (zanadiqah) entered the presence of the Emam Reza (A.S.) with whom was a group of people, Abu-l-hasan (the Emam) said to him.
"Dost thou see that if the correct view is your view-- and it is not your view - then are we not equal? All that we have prayed, fasted, given of the alms and declared of our convictions will not harm us."
The unbeliever remained silent. Then Abu-l-HasanA.S), said, "If the correct view is our view - and it is our view - then have not you perished and we gained salvation?"
He said, "God's mercy be upon thee. Then let me know, how is He and where is He?"
Abu-l-Hassan(A.S) answered "Woe upon thee, surely the opinion thou hast adopted is mistaken. He determined the 'where', and He was, when there was no where; and He fashioned the 'how' and He was, when there was no 'how'. So He is not known through 'howness' or 'whereness' or through any form of sense perception, nor can He be gauged by anything."
The man said, "So then surely He is nothing (la shay) if He cannot be perceived by any of the senses."
Abu-l-Hasan(A.S) said, "Woe upon thee! When thy senses fail to perceive Him, thou deniest His lordship. But when our senses fail to perceive Him, We know for certain that He is our Lord and that He is something different from other things (shay' di-khilaf al-ashya)."
The man said, "Then tell me, when was He?"
Abu-l-Hasan(A.S) said, "Tell when He was not, and then I will tell you when He was."
The man said, "Then what is the proof of Him?"
Abu-l-Hasan(A.S), said, "Surely when I contemplate my body and it is impossible for me to increase or decrease its breadth and height, or to keep unpleasant things away from it or draw benefits to it, then I know that this structure has a maker and I acknowledge (iqrar) Him -- even though that which I had seen of the rotation of the celestial sphere through His power; the producing of clouds, the turning about of the winds; the procession of the sun, the moon and the stars; and others of His wondrous and perfectly created signs (ayat), had (already) made me know that (all) this has a Determiner (muqaddir) and Producer (munshi)."
The man said, "Then why has He veiled Himself (from men)?"
Abu-l-Hasan(A.S.) replied, "Surely the veil is upon creatures because of the abundance of their sins. As for Him, no secret is hidden from Him during the day or the night."
The man said, "Then why does the sense of sight perceive Him not?"
Abu-l-Hasan(A.S.) answered. "Because of the difference between Him and His creatures, who are perceived by the vision ot the eyes, whether their own or others. Then He is greater than that sight should perceive Him, imagination encompass Him, or the power of reason delineate Him."
The man said, "Then define His limits (hadd) for me."
He answered, "He has no limits."
The man asked, "Why?"
He answered, "Because every limited thing (mahdud) ends at a limit. If limitation (tahdid) is possible, then increase is possible. If increase is possible, then decrease is possible. So He is unlimited. He neither increases nor decreases. Nor is He capable of being divided or imagined."
The man said, "Then tell me about your saying that He is Subtle, Hearing, Seeing, Knowing and Wise. Can He be the Hearing without ears, the Seeing without eyes, the Subtle without working with the hands and the Wise without workmanship (sanah)?"
Abu-l-Hasan(A.S.), said, "Surely a person among us is subtle in accordance with (his) skill in wokmanship. Hast thou not seen the man who undertakes a task and is subtle in his handling of it, so that it is said, 'How subtle is so and so!' Then how should it not be said of the Majestic Creator that He is Subtle, when He creates a subtle and majestic creation, places in its living creatures their souls, creates every kind different in from its own kind, and none resembles another? Each possesses in the composition of its form a subtlety from the Subtle and Aware Creator.
"Then we looked upon the trees and their bearing of delicate things, whether edible of inedible, and we said at that, 'Surely our Creator is Subtle, (but) not like the subtlety of His crearures in their workmanship. 'And we said, 'Surely He is Hearing for not hidden from Him are the sounds of His creatures between the Throne and the earth, from a mote to what is larger than it, and in the land and the sea. And their words are not confused by Him.' At that we said, 'Surely He is Hearing, but not through ears.'
"Then we said, 'Surely He is Seeing, but not through eyes, for He sees the trace of a black speck on a dark night on a balck stone. He sees the tracks of an ant on a pitch-black night. He sees what is harmful for it and what beneficial, and the result of its cohabitation, and its young and descendents. 'And at that we said, 'Surely He is Seeing, but not like the sight of His creatures'."
The man did not leave until he had embraced Islam. The Emam(A.S.), said other things as well.

Inter-Faith Debate
On various occasions, al-Mamoon tried to force Imam Reza (A.S.) into the arena of complex debates with various groups and creeds. He used to conduct scientific and intellectual sessions to which he invited giant thinkers, leading scientists, the atheists of the century, and debaters whose scientific might was feared and before the stubbornness of whose complex arguments the evidence was muted and due to the fierceness of whose doubt the proof was weakened. In all such debates, the Holy Imam(A.S.) would come out victorious over his opponents due to the tremendous power of knowledge he divinely possessed without forcing himself into the sophistry of arguments to which some might have resorted in order to demolish the structure of his opponent's argument and weaken his ability to provide evidence. Rather, he depended in his debate upon honest arguments in order to prove right to be right, his miraculous ability of conviction, and his calm stylistic method.Al-
Nawfali Warns the Imam
Al-Nawfali tried to warn the Holy Imam(A.S.) against attempting to deal with the debates of such people when the Holy Imam(A.S.) asked him why al-Mamun had invited him to debate them, for al-Mamun had asked the Catholic archbishop, the High Rabbi, leading Sabians, the Hindu high priest, followers of Zoroaster, Nestus the Roman medical scientist, and a group of orators, to enter into a scientific debate with Imam Reza (A.S.). He sent Yasir the servant to the Holy Imam(A.S.) to tell him about the time when the debate would start, requesting him to attend. When Yasir went out and al-Nawfali was alone with the Holy Imam(A.S.), the Holy Imam (A.S.) turned to him and asked him in the form of a dialogue, "O Nawfali! You are an Iraqi, and the heart of an Iraqi is not severe; so, what can you gain from causing your cousin to require us to meet with disbelievers and rhetoricians?" Al-Nawfali answered, "May my life be sacrificed for yours! He wants to put you to test, and he loves to know how much knowledge you possess. He has, indeed, built his assumption on a shaky foundation, and doomed, by God, what he has built." He asked, "And what has he built?" He answered, "Scholars of kalam and innovators are opposite of the scholars. A scholar does not deny the undeniable, whereas rhetoricians and polytheists are people who deny and try to prove what is not true. If you argue with them and tell them that God is One, they would say, `Prove His Oneness,' and if you say that Holy Prophet Muhammad (S.A.W.) is the Messenger of God, they would say, `Confirm his Message,' then they would press their lies on a person while he tries to disprove their lies, and they would continue to prove that he is mistaken till he abandons his argument; so, beware of them, may my life be sacrificed for you." He smiled and asked, "O Nawfali! Do you fear that they will disprove my argument?" He answered, "No, by God! I have never worried about you, and I hope God will enable you to have the upper hand over them." The Holy Imam(A.S.) asked again, "O Nawfali! Would you like to know when al-Mamun will feel regretful?" He answered, "Yes." He said, "When he hears me argue with the people of the Torah quoting their own Torah, with the people of the Gospel (Bible) quoting their own Gospel, with the people of the Psalms quoting their own Psalms, with Zoroastrians arguing in their Persian language, with the Romans in their own Latin, and with rhetoricians using their very rhetoric. So, if I closed all the avenues of argument in the face of each arguing party and disproved his claim, making him renounce his statement from its onset and referring to my own statement, then al-Mamun would know that he would not achieve what he aspires. It is then that he will feel regretful; We are from God's, and Unto Him is our return."Thus does the Holy Imam(A.S.) show that he was taking lightly and was not concerned about such persons whom al-Mamun wished to gather together against him trying to embarrass him with their falsification and arguments which he hoped might close for the Holy Imam (A.S.) all the avenues of argument. When the session starts and the Holy Imam (A.S.) is invited to join it, discussion starts and the Holy Imam (A.S.) starts his debate with the Catholics, making the Bible his reference to prove his own defense of the Unity of God and disprove the Godhead of Jesus Christ (A.S.) by those who regarded him as a god besides God. Then he follows with a magnificent discussion proving that the Bible in circulation today is not the same which God had revealed to Jesus Christ (A.S.) and that it is authored by some of the disciples of Jesus Christ (A.S.) who are the authors of the four gospels, depending in his argument on the fact that the details presented by each one of them stand in flagrant contradiction with those of the other. The Catholic archbishop slipped into an obvious self-contradiction; for he on one hand sanctified the authors of the four gospels and held them above lying while, on the other hand, he admitted to the Holy Imam(A.S.) that they did tell lies about Jesus Christ (A.S.).Then the Holy Imam (A.S.) goes to debate the High Rabbi, scholar of the Jews, to prove the prophethood of Holy Prophet Muhammad (S.A.W.) from the previously revealed divine testaments, after which he follows with a very logical debate. Having argued with him that one of the requirements of a Prophet was to perform something all other creation are unable to perform, he asked him about the reason why they, the Jews, refrained from believing into the miracles of all prophets other than Moses (A.S.) son of Imran, and the High Rabbi answered him saying, "We cannot admit the prophethood of any who professes prophethood except after bringing us knowledge similar to that brought by Moses." Imam Reza (A.S.) said to him, "Then how come you admitted the prophethood of other prophets who preceded Moses (A.S.) who did not split the sea, nor cleave the stones so that twelve springs would gush forth from it, nor took their hands out shining white as Moses did, nor did they turn a cane into a snake?!" It was then that the High Rabbi overcame his stubbornness, submitted to the argument, and admitted that any supernatural act beyond human capacity was indeed a proof of prophethood.The Holy Imam (A.S.) asked him then about the reason why they did not believe in the prophethood of Jesus Christ (A.S.) despite the fact that he brought forth miracles beyond human capacity such as bringing the dead back to life, healing those who were born blind and the lepers, and about the reason why they did not believe in the prophethood of Holy Prophet Muhammad (S.A.W.) despite his bringing an extra-ordinary miracle, that is, the Holy Qur'an while he was neither a scholar nor a writer. The High Rabbi had no answer at all.Then came the turn of the Zoroastrian high priest whom the Holy Imam(A.S.) debated depending on the priest's belief in the prophethood of Zoroaster. The Zoroastrian tells the Holy Imam(A.S.) that Zoroaster brought them what no other man had ever brought them before. "We did not see him," he continues, "but the stories of our ancestors told us that he legalized for us what no other person before made legal; so, we followed him." The Holy Imam(A.S.) asked, "You believed in the stories which came to you about him, so you followed him, didn't you?" "Yes," he answered. The Holy Imam (A.S.) said, "This is the case with all other nations. Stories came to them about what the prophets had accomplished, what Moses (A.S.), Jesus (A.S.), and Muhammad (S.A.W.) had all brought them, so why did you not believe in any of these prophets, having believed in Zoroaster through the stories that came to you about him saying that he brought forth what others did not?"
Holy Imam's Debate With the Sabian
The Zoroastrian high priest had no more to say. The Holy Imam(A.S.) then turned to the debate's witnesses, having finished debating with the chief representatives of those creeds, asking anyone else to go ahead and put forth any question he had, everyone abstained from doing so. It was then that Imran the Sabian, who was one of the most distinguished scholars of the science of kalam of his time, approached the Holy Imam (A.S.) and asked him how he could prove the existence of the Creator, and the discussion between them delved into the deepest depths of this complex question, while the Holy Imam answered the man's questions through obvious scientific facts in a gloriously simple way. Among the questions Imran asked was: "Master! Was the Being known to Himself by His Own Self?" The Holy Imam(A.S.) said, "Knowledge is acquired by something which would negate its opposite, and so that the thing itself would be existing through what it is negated about it, without the existence of anything which contradicts its existence so that a need arises to negate that thing about itself by defining what is known about it. Do you understand, O Imran?" He said, "Yes, by God, master! Tell me, then, by what means did He come to know what He knew, by a pronoun or by something else?" The Holy Imam (A.S.) said, "If it had been by a pronoun, would He then find anyway not to establish for that pronoun a limit where knowledge ends?" Imran answered, "Yes, He will have to find such way." The Holy Imam(A.S.) then asked him, "Then what is that pronoun?" Imran could not provide any answer. The Holy Imam (A.S.) said, "Is it alright if I ask you about the pronoun and you define it by another pronoun? If you answer in the affirmative, then you would make both your claim and statement void. O Imran! Ought you not come to know that the One cannot be described by a pronoun, and would not be described except by a verb, by deed, by action, and He cannot be expected to be parts and kinds like human beings?"Then Imran asked him, "Master! The knowledge I have says that the being is changed in his essence by his action of creating..." The Holy Imam (A.S.) said, "Does your statement, O Imran, mean that the being does not in any way change its essence except when it affects its own essence in a way which changes it? O Imran! Can you say that the fire changes its own self, or that the heat burns itself, or have you seen anyone seeing his own vision?" Imran said, "No, I have not seen that; could you please tell me, master, is it in that in the creation, or is it the nature of creation in it?" The Holy Imam (A.S.) said, "Yes, O Imran, He is above all of that; He is not in the creation, nor is the creation in Him; He is elevated above that, and bad indeed is your knowledge about Him, and no might except in God. Tell me about the mirror: are you in it or is it in you? If neither one of you is in the other, then how did you come to see your own self's reflection in it?" Imran said, "Through the light between myself and itself." The Holy Imam (A.S.) said, "Can you see of that light more than what you can see with your own eyes?" He answered, "Yes." The Holy Imam (A.S.) said to him, "Then show it to us..." It was then that the man was too baffled to say a word. The Holy Imam (A.S.) said, "I do not see the light except leading you and the mirror to come to know each without being in either one of you. There are many such examples which the ignorant simply cannot observe, and God Has the greatest example."Thus did the Holy Imam(A.S.) face the challenge of Imran the Sabian's doubting method, demolishing its structure and dispelling the ambiguity of the complex doubts which he could not understand till vision became clear to him. The Holy Imam (A.S.) did not determine an evidence except after building it with simple easy to understand proofs out of the everyday life of man in order not to leave any way for the opponent to doubt after transforming a most complex theory into an easy and commonsense idea, all of that by employing a very beautiful and miraculous style.

Safeguarding Islam
Those who have hitherto examined Islam's methodical report-card, maintain that the age of the reign of Harun and that of Mamun have been known as a brilliant scholarly epoch in the literary history of Islam.
In the course of this eminent period of time the Muslims succeeded in becoming acquainted with the western scientific findings through translating the Greek work, and thereafter they profoundly studied those versions and added large numbers of new scholarly subjects of research such as studies on theoretical and rational sciences to those themes.
The Muslim scientists attained success to discover many acids like nitrus acid, sulphuric acid and other substances as the infernal stone.
The access to the western philosophy as well as the availability of the Greek written sources and the acquaintance with the views and doctrines of Aristotle, Socrates, Plato and their disciples, paved the way for the Muslim scholars to develop their studies on natural sciences and on metaphysical issues as well.
The freedom of thought provided and permitted by Islam made facilities for the scholars of other religions to hold debate sessions on exchanging their ideas in connection with questions and problems concerning the precepts and doctrines of their creeds.
Likewise, the expansion of the Islamic territories caused the association of the Muslims with non-Muslim peoples including the Jews, the Christians and even too many atheists.
These opponents tried to propound disputes and invent doubtful allegories about the faith of the Muslims.
The situation was very critical and the ideological assault seemed to be more dangerous than a military invasion in those days.
Mamun,the Abbasid caliph was a very clever, shrewd and cunning politician. In order to get closer to Imam Reza (A.S.), he would arrange inter-faith scholarly debates, and would usually invite the Holy Imam(A.S.) to participate in these meetings. There he would pose the most complicated religious and scientific questions to the scholars.
On Tuesdays, Mamun used to invite scholars of different religious persuasions to Marw. After meals he would perform ablution, perfume himself and enter the gathering. The debate hall was furnished with the most expensive carpets, and the debate would continue until evening.
Imam Reza (A.S.), however, knew the objectives behind all this and would always warn his close followers not to be deceived by Mamun's actions. He would say: "By Allah! None other than he will kill me. There is no other option, we should be patient till this ends."
Mamun's real purpose in inviting the intelligentsia and top scholars from different lands to debate with the Holy Imam(A.S.), was his vain desire to see one of the scholars overcome Imam Reza(A.S.)-the true heir and real successor of the Holy Prophet of Islam(S.A.W.). In this way Mamun wanted to degrade the exalted position attached to the person of the Holy Imam(A.S.) among the scholars.
Learned scholars of the Jews Christians, Zoroastrians, idol and star-worshippers and the atheists, as well as the different sects of Islam, would debate with Imam Reza (A.S.) and finally leave the gatherings in admiration for the God-given knowledge of the Holy Prophet of Islam's(S.A.W.) rightful successor. The Holy Imam(A.S.) used to answer them from their own books and on the basis of their own reasoning by presenting logical explanations in their own language.
All this had a great impact upon the revival and spread of the Islamic teachings.Imam Reza(A.S.), thus successfully safeguarded and propagated the ideals,teachings and principles of Islam.In this way the Holy Imam (A.S.), also protected the rights of the Muslims and awakened them.
After every debate, Imam Reza's(A.S.) popularity would soar, and respect and esteem for him would grow higher among the scholars, to the extent that people used to regard the Holy Imam(A.S.) more worthy of the caliphate. The spies of Mamun would keep him informed about the general public opinion regarding the proceedings of the debates, making the caliph more jealous and more spiteful of the Holy Imam(A.S.).
But for the time being Mamun maintained his outward behaviour of respect and on his request Imam Reza (A.S.) compiled two books: "Fiqh ur-Reza(A.S.)" and "Tibb ur-Reza(A.S.)", which respectively deal with the principles of Islamic jurisprudence and prescriptions of health and hygiene.

Issue of Badaa
In another session, al-Mamoon invited him to debate Sulayman al-Maroozi, Khurasan's scientist in kalam(theology), and the debate between them dealt with some significant topics which were being debated then by scholars of the science of kalam, and the starting-point of the discussion was the issue of Badaa(change in an earlier divine ruling). The Holy Imam (A.S.) explained its sound meaning, indicating that the Sublime and Great God had innermost knowledge which nobody but He knew, and that was the source of badaa and knowledge which He taught His angels and Prophets.To explain it in a way which would remove all confusion and ambiguity, we can say about badaa is that God makes manifest that His Will is linked to an advantage which necessitates it, and the apparent reality is that His Will is hinging on what is opposite to it. Then He after that makes manifest His actual Will when the advantage is satisfied from all aspects and the reasons for which it was not previously manifested are removed, and it appears to the creation as if God willed to abandon His first Will, hence it is in the view of creation, not in the reality of Will, badaa. This is the theory of badaa in its simple logical context which Imamis (Shi'as) uphold and which some people misunderstood and misinterpreted, giving it a wrong meaning which necessitated attributing ignorance

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