Brief Answer: "Taqiyya" refers to the concealment of one’s beliefs or religious practices out of fear of significant harm or to protect a crucial interest. 

The Quran states: "Believers should not take disbelievers as protectors instead of believers; whoever does this will not have a relationship with God, unless you do so to protect yourself from them." (Quran, 3:28)

The philosophy of "Taqiyya" is that when expressing true beliefs poses risks to one's life, honor, or wealth without any significant benefit, it is logical to preserve resources through "Taqiyya" for more critical situations.

Detailed Answer: "Taqiyya," linguistically means caution or safeguarding oneself and is variously defined as the concealment of one's beliefs or religious practices due to fear of harm or for another significant benefit, such as maintaining unity and avoiding conflict with common enemies. This concept has Quranic roots, illustrated by an incident involving a companion of the Prophet Muhammad (peace be upon him & his progeny), during a time when Muslims were a minority; it states: "Let not the believers take the disbelievers as allies rather than the believers. And whoever does that has nothing with Allah, except when taking precaution against them in prudence." (Quran, 3:28). This verse clearly addresses the issue of Taqiyya in the face of irrational enemies, leaving no room for negotiation.

The story of 'Ammar facing the polytheists, who forced him to utter words against Islam and the Prophet (peace be upon him & his progeny), is well-known. Under duress, he complied with their demands and later, tearfully fearing for his faith, approached the Prophet who reassured him that coerced statements do not harm one’s faith. This event led to the revelation: "Whoever disbelieves in Allah after his belief... except for one who is forced [to renounce his religion] while his heart is secure in faith." (Quran, 16:106). 

Additionally, the story of the believer from Pharaoh's people, who hid his faith and argued against the killing of Moses by saying, "Would you kill a man [merely] because he says, 'My Lord is Allah,' while he has brought you clear proofs from your Lord?" (Quran, 40:28) This narrative from the Quran praises the man's tactful concealment of his faith, indicating Divine approval of his Taqiyya. Islamic traditions are replete with references emphasizing the importance of Taqiyya, describing it as the believer's shield, which preserves them from enemies and conserves their strength for critical moments. Taqiyya is deemed part of faith, and a believer without Taqiyya is likened to a body without a head. It is considered one of the best deeds because it prevents the wasteful expenditure of energy. 

Moreover, Taqiyya serves a clear philosophical purpose: when openly expressing one's true beliefs could result in life-threatening danger without yielding substantial benefits, rationality dictates that one should not squander their energies frivolously but should preserve them through Taqiyya for more critical moments. Taqiyya is likened to a believer's armour, not a means to shirk responsibilities but a strategic tactic in warfare to protect one's forces from the enemy until the right moment for action.

Brief Answer: Abrogation and bada' share the concept of the gradual manifestation of Divine will to His servants. The key difference is that abrogation pertains to legislative matters (e.g., the change of the Qiblah direction), while bada' pertains to existential matters (e.g., lifespan changes). Abrogation is accepted by all Muslims, where a law thought to be eternal might later be revoked by the Prophet (peace be upon him) and replaced with another, as historically noted in the change of the Qiblah. This is essentially a form of bada', though typically referred to as "abrogation" in legislative contexts and "bada'" in existential matters.

Detailed Answer: When discussing the meanings of "abrogation" and "bada'," it is crucial to understand that these two theological concepts have both similarities and distinctions. To understand these, we must first grasp the precise meanings of each term.

Meaning of Abrogation: Abrogation, linguistically, means to erase or remove something. In the Qur'an, this term is used in two senses:

1. Transcribing text from one copy to another, as seen in the context of recording actions in Surah Jathiya: "This is our book speaking unto you in truth. We were transcribing what you used to do."
2. The removal and cancellation of a religious ruling that appeared permanent, replaced by a subsequent decree. For example, initially, marriage to non-believers was permissible in early Islam, as Prophet Muhammad (peace be upon him & his progeny) married his adopted daughter Zainab to Abul-Ass before he accepted Islam, but this ruling was later abrogated.

Similarity between Abrogation and Bada': In bada', there is also a cancellation, but not of religious decrees; instead, it involves existential matters, indicating that God records a decree for a person based on their current state. If that person performs good deeds, like kinship ties or aiding the poor, God may change the original decree to a new one. This change is known to God from the outset, making it unknown only to us, not implying ignorance in God.

Opponents' Critique of Abrogation and Bada': Jewish beliefs, for instance, reject any change in decrees or laws, adhering to the notion that "God's hands are tied." This view similarly rejects abrogation in decrees, equating it to suggesting ignorance in God about the wisdom of decrees, which is considered impossible.

Argument against Opponents of Abrogation: Critics argue that if God changes a ruling, it either implies He was unaware of the underlying wisdom (implying ignorance) or that He knows it but decides to change, which contradicts divine omnipotence. We respond that while the notion of abrogation as discovering a mistake in earlier legislation implies ignorance and is unacceptable, abrogation in divine law is tied to specific times and circumstances known to God, who hides the end time from His servants. The previous decree was valid for its time but not meant to be eternal.

Distinctive Point of Abrogation and Bada': Thus, while both abrogation and bada' reflect the gradual manifestation of God's will, they apply differently: abrogation in legislative contexts and bada' in existential matters. Notably, scholars like Qadi Abdul Jabbar al-Mu'tazili and from Shi'a Islam, figures like Sheikh Mufid and Sheikh Saduq, see these concepts as parallel and compatible, underscoring the dynamic aspect of divine will in guiding humanity.

Answer: Those among the Sunnis who criticize Shia for their belief in Bada' should note that this belief, in the same sense accepted by Shia, exists in their sources, including interpretations by Sunni scholars like Tabari, Qurtubi, and Ibn Kathir under verse 39 of Surah Ra'd -- "Allah erases what He wills and confirms, and with Him is the Mother of the Book." They quote the second caliph saying during his circumambulation of the Kaaba: "O Allah, if you have written me among the people of happiness, keep me in it, and if you have written me among the people of misery and sin, erase it and establish me among the people of happiness and forgiveness, for You erase and confirm, and with You is the Mother of the Book."

Erasing someone's name from the list of the miserable and adding it to the group of the blessed, manifesting a new divine will due to causes like prayers, is precisely Bada'.

Answer: In Shia belief, "Bada'" means that God initially sets a destiny for a person based on their current situation. Later, if the person performs good deeds by using his will power, such as maintaining ties of kinship and helping the poor, God changes the previous destiny and records a new one for them. This change in destiny is called "Bada'." Sunni sources also contain instances that confirm the Shia interpretation of Bada'.

Brief Answer: Shi'as believe that the hadiths of the infallible Imams (peace be upon them) are the hadiths of the Prophet (PBUH) and represent his exact Sunnah. Shi'as trust them for accurate understanding and transmission of the Prophet's Sunnah because they are considered purified by God as mentioned in the "Verse of Purification"; they are the real "People of Remembrance" and the true holders of prophetic knowledge: "I am the city of knowledge and Ali is its gate."

Additionally, the Ahlul Bayt are considered as part of the "Thaqalayn" (the two weighty things), thus their traditions, alongside the Quran and the Sunnah of the Prophet, are authoritative. The Prophet (PBUH) has instructed Muslims to adhere to the Quran and his progeny to avoid misguidance. The Prophet (PBUH) conveyed a significant portion of the Quranic knowledge and truths to people, but some aspects, either due to the lack of appropriate conditions for their disclosure or because it was more appropriate for them to be revealed later, were entrusted to his pure progeny to elucidate.

Shi'as are the primary promoters of the Prophet's (PBUH) Sunnah; unlike after the Prophet's (PBUH) demise, Shi'as never prohibited the narration of his hadiths and consistently relied on them to better understand Islam and the Quran. In contrast, Sunnis long prohibited the narration of the Prophet's hadiths and maintained that "The Book of Allah is sufficient for us," ignoring that the Quran should be interpreted with the Prophet's Sunnah and the guidance of the Ahlul Bayt.

Detailed Answer: Shi'ism and the Narrations of the Prophet

Shi'as not only remember the Prophet’s (PBUH) hadiths, but they actually pay more attention to them than other Muslims do, obtaining them from the Ahlul Bayt and righteous companions like Salman, Abu Dharr, and Ammar. Shi'as truly adhere to the Prophet’s Sunnah. Fortunately, the number of narrations that Shi'as report from the Prophet is extensive and significant. Unlike in Sunni history, Shi'ism has never experienced a prohibition against narrating the Prophet’s hadiths. Consequently, in addition to hundreds of narrations from the early Islamic period until now, some Shi'a scholars have independently collected narrations from the Prophet reported by the Ahlul Bayt and Shi'as in separate books like "Nahj al-Fasahah" and "A Journey through the Prophetic Biography."

Narrations from Ahlul Bayt are Narrations from the Prophet:

An important aspect of Shi'a belief regarding prophetic narrations is that Shi'as consider that the Imams, having received everything from the Prophet, convey hadiths that originate from their forefathers who received them directly from the Prophet. Imam Sadiq (AS) emphasized this lineage of knowledge in a narration, asserting that his narrations trace back through his ancestors directly to the Prophet (PBUH).

When Jabir asked Imam Baqir (peace be upon him) to validate his narrations, the Imam responded that his hadiths come from his father, from the Prophet. The Imams usually did not mention the chain of transmission up to the Prophet when it was clear, except when in the presence of Sunnis, making some Sunni narrations directly connected to the Prophet.

Moreover, the Prophet (PBUH) described Imam Ali (AS) with: "I am the city of knowledge and Ali is its gate," indicating that Imam Ali and his descendants’ teachings are derived from the knowledge that came directly from the Prophet.

Additionally, in the famous Hadith al-Thaqalayn, the Prophet identified the Ahlul Bayt alongside the Quran as the key sources of guidance for Muslims, underscoring that adhering to both would prevent misguidance. The Prophet disclosed significant Quranic knowledge to the people, but the rest, which was either not suitable for immediate revelation or was deemed appropriate for later explanation, was entrusted to his infallible progeny.

In conclusion, preserving what the Prophet had articulated and elucidating what was not spoken was entrusted to the Prophet's Ahlul Bayt, making them the authoritative source for understanding the Quran and the Prophet's Sunnah. Even Ibn Hajar, a strict Sunni scholar, acknowledged the significance of the Quran and the Ahlul Bayt as sources of divine knowledge and emphasized adherence to them. Thus, Shi'as follow the teachings of the infallible Imams who are free from error according to the "Verse of Purification" and whose words reflect the true Sunnah of the Prophet.

Answer: Shia scholars have consistently denied the notion of Quranic distortion throughout history, emphasizing that Shias acknowledge only the existing Quran familiar to all Muslims.For example, Sheikh Saduq has clearly stated, "Our belief is that the Quran, which was revealed to the Prophet by God, is the same familiar text among the people, and anyone who claims otherwise is a liar."

Sayyid Murtaza also writes, "Nothing has been omitted from the Quran, and the views of some from the Imamiyya and Hashwiyya that suggest otherwise should not be considered."

Sheikh Tusi believes that discussing the Quran as lacking or having excess is not a worthy subject for this divine book. He asserts, "To say the Quran has additions is unanimously rejected. The notion that it might lack verses is also opposed by all Muslims, and such a view should rightly be rejected in our sect."

Kashif al-Ghita’ also held that "there is no doubt about the Quran being preserved from any diminishment or addition, a feature granted by God and explicitly mentioned in the Quran itself. All scholars have consistently agreed on this, and any opposing view is rare and should not be regarded."

These views are prevalent among both early and later Shia scholars, and it's impossible to list them all here. This belief is a genuine conviction among all Shia scholars throughout history, based on logical and traditional evidence (including Quranic verses and narrations).

Answer: Logically, the history of the Quran shows that it was never a neglected or forgotten book that could be easily altered. As soon as a verse was revealed, it was recorded by scribes, whose numbers are reported to range from 14 to around 400. Hundreds of memorizers existed during the Prophet's time who would immediately memorize the verses. The Quran was the primary form of worship, the constitution of Islam, and an integral part of Muslims’ lives. It is logically implausible for such a book to be subject to distortion.

Answer: Islamic narrations from the Imams also emphasize the authenticity and completeness of the Quran. For instance, Imam Ali (peace be upon him) in Nahj al-Balagha states that God sent down a book which fully details everything and allowed the Prophet to live long enough to complete the religion with the Quran. Throughout Nahj al-Balagha, there is no mention of Quranic distortion; instead, it affirms the completeness of the Quran.

Moreover, numerous reliable narrations instruct that when there is a contradiction in narrations, they should be compared with the Quran; what aligns with it should be accepted, and what does not should be discarded. This method of verification presumes the Quran’s incorruptibility since if it were distorted; it could not serve as a reliable standard.

In addition to all this, the famous Hadith of Thaqalayn, which is widely quoted in both Sunni and Shi'a texts, says that the Prophet Muhammad (peace be upon him & his progeny) stated: "I leave behind among you two precious things, the Book of Allah and my Progeny, my Ahlul Bayt. If you cling to them, you will never go astray." This meaningful hadith clearly shows that the Holy Quran and alongside it, the Progeny of the Prophet, are a very secure refuge for guiding people until the end of time. If the Quran had been subjected to tampering, how could it have been a secure refuge and saved people from any kind of misguidance?

Overall, while distortion theories exist within the heritage of both Sunni and Shia narratives, leading Shia scholars and the general Shia doctrine steadfastly recognize the Quran as immaculate and preserved, aligning with the foundational Islamic belief in the divine protection of the Quran.

Brief Answer: Shia opponents, due to their misunderstanding of the concept of "Bada'" within Shia belief, criticise it as stemming from Jewish ideas and leading to changes in divine knowledge and attributing ignorance to God. They accuse Shias of disbelief, even though "Bada'" does not imply ignorance or unawareness in God, and according to Shia traditions, one must disassociate from anyone who claims such.

Detailed Explanation: Shia opponents, due to their incorrect perception of Bada' as a negation of God's knowledge, either knowingly or unknowingly, criticize and accuse Shias of disbelief because of this belief. Fakhr Razi does not accept the belief in Bada' because he sees it as causing changes in divine knowledge. Abu al-Hasan al-Ash'ari also holds that a group of Shias believes Bada' allows for unfulfilled divine intentions, suggesting changes occur in divine will. Some also interpret belief in Bada' as attributing ignorance to God, and since anyone who denies God's knowledge is considered an infidel, Shias are accused of disbelief for their belief in Bada'.

Clarifying the Correct Meaning of Bada' in Shia Islam by Differentiating Between Inherent and Active Divine Knowledge Those who object to Bada' and see it as causing changes in divine knowledge or attributing ignorance to God are confusing the inherent, eternal knowledge of God with active, created knowledge. Essentially, Bada' does not occur in God's inherent and absolute knowledge; therefore, the objection is unfounded. Instead, Bada' occurs in the tablet of destinies, which represents active and created knowledge.

In other words, God initially records a destiny for a person based on their current situation in the tablet of destinies. Later, if this person performs good deeds, such as maintaining family ties or helping the poor, God then changes the previously recorded destiny to a new one. This change in destiny is called "Bada'." However, with His inherent and absolute knowledge, God is aware of all these destinies, past and future, and records them in another tablet known as Umm al-Kitab or the preserved tablet. "Knowledge of change" differs from "change in knowledge," and Bada', itself, is subject to divine knowledge.

In reality, it is people who perceive a phenomenon but are unaware of other occurrences. When something unforeseen happens, they say, "Bada' has occurred to God," using the term metaphorically from a human perspective, while in reality, it is God revealing to people something previously hidden from them.

Shia traditions clearly state that Bada' does not conflict with God's inherent knowledge and does not imply ignorance or unawareness in God; indeed, attributing ignorance to the absolute, all-knowing God is impossible. Imam Sadiq (peace be upon him) has been quoted as saying, "Bada' in the sense of ignorance and unawareness does not apply to God, and anyone who claims otherwise should be disavowed"; this person is considered an unbeliever! Imam Musa al-Kadhim (peace be upon him) also stated, "Bada' never occurs in anything for God unless He already knew it; certainly, Bada' does not occur out of ignorance for God" and so on.

Therefore, how can one, with such explicit narrations, accuse followers of the School of Ahlul Bayt (peace be upon them) of believing that God was unaware of something before it happened and only became aware after its occurrence?

Statements of Shia Scholars on the Unanimously Agreed Upon Belief in Bada' 

Sheikh Saduq, citing traditions, states, "According to us, anyone who claims that something new has appeared to God today that He was not aware of yesterday is an infidel, and disavowal of such a person is obligatory." Along with Sheikh Saduq, Allama Agha Bozorg Tehrani in his book Al-Dhari'ah, after discussing the literal meaning of Bada' as a change of opinion and new knowledge previously unknown—which is impossible for God as it implies ignorance and incapacity, which the Imamiyah, unlike other sects, absolutely negates from God—labels the attribution of this belief to the Shia by some Sunni scholars in their interpretations as a great slander. He then adds that the belief in Bada' as understood by the Shia should be held by every Muslim against the Jews who say, "God's hand is fettered."

Indeed, one of the criticisms of the Jews by the Quran is their belief that the act of creation has finished, and they believed, "The pen has dried with what will come to pass." Thus, opponents and critics of Shia should be asked: From which credible Shia source and which Shia individual have you found such a belief that attributes ignorance and incapacity to God through the belief in "Bada'"? Clearly, these critics do not have an accurate understanding of Shia beliefs, have not properly grasped the Shia view of Bada', and are completely unaware of the explicit narrations from the head of the Shia school, which clearly negates ignorance, especially concerning the issue of Bada', and seeks disassociation from attributing ignorance to God, especially in matters of Bada'.

Answer: The Quran itself asserts its protection from distortion. For example, Surah Hijr, verse 9 states, "Indeed, it is We who sent down the Quran and indeed, We will be its guardian." Another example is in Surah Fussilat, verses 40-41, which emphasize that falsehood cannot approach the Quran from before or behind it, asserting its incorruptibility.