What is taqiyyah (dissimulation)? Is it used by Ahl as-Sunnah (Sunnis)?

Firstly: 

Taqiyyah, in the usual and well-known sense, is one of the
basic principles of the Ithna-Ash‘ari Raafidis; Ahl as-Sunnah wa’l-Jamaa‘ah
differ from them concerning it and it is something that takes them beyond
the boundaries of the straight path of Allah. 

Taqiyyah in their religion means presenting outwardly
something that is different from what one believes inwardly, as an act of
religious devotion. Thus they attributed lying and deceit to the religion of
Allah, wrongfully and out of enmity. 

This corrupt belief has nothing to do with
the beliefs (‘aqeedah) of Ahl as-Sunnah. According to Ahl as-Sunnah, lying
is one of the attributes of the hypocrites. A person may keep on lying and
persist in lying until he is recorded with Allah as a liar. These people
tell lies and persist in lying in all things, then they regard that as part
of their beliefs and religion. 

The way of Ahl as-Sunnah wa’l-Jamaa‘ah is
based on truthfulness and justice; lying is not part of their religion,
praise be to Allah. 

Shaykh al-Islam Ibn Taymiyah (may Allah
have mercy on him) said: The Raafidis are the most ignorant and mendacious
of sects, and the furthest removed from any knowledge of the texts or
rational evidence. They regard taqiyyah as one of the basic principles of
their religion, and they tell lies about Ahl al-Bayt (the Prophet’s family),
the extent of which is known only to Allah. They even narrated from Ja‘far
as-Saadiq that he said: “Taqiyyah is my religion and the religion of my
forefathers.” But taqiyyah is one of the signs of hypocrisy; in fact in
their case, they say verbally that which is not in their hearts, and this is
the essence of hypocrisy.

End quote from Majmoo‘ al-Fataawa,
13/263 

He also said: 

As for the Raafidis, the basis of their
innovation is heresy and the deliberate lying that is widespread among them.
They affirmed that when they said: Our religion is taqiyyah. This means that
one of them says verbally something other than what is in his heart, and
this is lying and hypocrisy. Yet despite that they claim that they are the
(true) believers, to the exclusion of other Muslims, and they describe the
earliest believers as apostates and hypocrites, when they are the ones who
deserve this description. There are no people among those who outwardly
profess to be Muslims who are closer to hypocrisy and apostasy than them,
and there is no greater number of apostates and hypocrites in any other
group than in theirs.

End quote from Minhaaj as-Sunnah an-Nabawiyyah,
1/30 

It says in al-Mawsoo‘ah al-Muyassarah
(1/54), which discusses the basic beliefs of the Shi‘ah: 

Taqiyyah: They – meaning the Imami Shi‘ah
– regard it as one of the basic principles of their religion, and they
regard the one who does not practise it as being the same as one who does
not pray. It is obligatory and it is not permissible to refrain from it
until the hidden imam appears. Whoever refrains from it before he appears
has gone beyond the pale of the religion of Allah, may He be exalted, and
the religion of the Imamis.

End quote. 

Dr. Naasir ibn ‘Abdullah al-Qafaari said: 

Al-Mufeed defined taqiyyah for them as
follows: Taqiyyah means concealing the truth, concealing belief in it,
concealing one’s true beliefs from those who differ from one and not showing
openly that which may lead to negative consequences in religious or worldly
terms. 

Thus al-Mufeed defined taqiyyah as
concealing beliefs for fear of harm from those who disagree with them –
namely Ahl as-Sunnah, as is usually the case when they use this term. In
other words, it means making an outward display of following the madhhab of
Ahl as-Sunnah (which they regard as false), and concealing the Raafidi
madhhab, which they believe is true. Hence some Sunnis think that those who
adhere to this belief are worse than the hypocrites, because the hypocrites
believe that what they are concealing of disbelief is falsehood, and they
make an outward display of being Muslims out of fear. But in the case of
these people, they think that what they are concealing is truth, and that
their path is the way of the Messengers and Imams. 

End quote from Usool Madhhab ash-Shi‘ah
al-Imaamiyyah, 2/805 

Secondly: 

Taqiyyah – as an idea or concession to be
used in extreme circumstances, on a temporary basis – is known to Ahl as-Sunnah,
but it is different from the taqiyyah practised by the Raafidis in both
general and specific terms. According to Ahl as-Sunnah, it is something to
be resorted to when one has no other choice, and it is an extraordinary
measure to be used only in times of extreme necessity. 

Ibn al-Qayyim (may Allah have mercy on
him) said: 

Taqiyyah means saying something contrary
to what one believes, for fear of harm that may befall him if he does not
resort to taqiyyah.

End quote from Ahkaam Ahl adh-Dhimmah,
2/1038 

The basis for it being permissible is the
verse in which Allah, may He be exalted, says (interpretation of the
meaning):

“Let not the believers take the
disbelievers as Awliya’ (supporters, helpers, etc.) instead of the
believers, and whoever does that will never be helped by Allah in any way,
except if you indeed fear a danger from them”

[Aal ‘Imraan 3:28]. 

The words “except if you indeed fear a
danger from them” mean: except in the case of one who fears their evil
in some countries or at some times. In that case, he may dissimulate (use
taqiyyah) by changing his outward behaviour (to protect himself from their
evil), without changing what he believes and intends in his heart. For
example, al-Bukhaari narrated that Abu’d-Darda’ said: We smile in the faces
of some people when our hearts are cursing them (inwardly).

End quote from Tafseer Ibn Katheer,
2/30 

It says in al-Mawsoo‘ah al-Fiqhiyyah,
13/186-187 

The view of the majority of Sunni scholars
is that the basic principle concerning taqiyyah is that it is disallowed; it
is only permissible in the case of necessity, and is permitted only to the
extent that is necessary. Al-Qurtubi said: The basic principle concerning
taqiyyah is that it is not permissible unless there is the fear of death,
severing of a limb or extreme harm, and there is no report to the contrary
as far as we know, except that which was reported from Mu‘aadh ibn Jabal
among the Sahaabah and from Mujaahid among the Taabi‘een. End quote. 

According to Ahl as-Sunnah, in order for
taqiyyah to be permissible, there should be fear of harm and the individual
should not have any other means of avoiding harm except by resorting to
taqiyyah. It is also stipulated that the harm that is feared should be of a
type that is extremely hard to bear. The one who resorts to taqiyyah should
also note that if he has any other option that does not involve committing a
haraam action, then he must choose it. He should also note that he should
not indulge in the concession to such an extent that it goes beyond the
limits of taqiyyah to the level of negligence by committing haraam actions
after achieving what is necessary. The basic principle concerning that is
what Allah, may He be exalted, said concerning the one who is forced by
necessity (interpretation of the meaning): “But whosoever is forced by
necessity without wilful disobedience, nor transgressing due limits, (for
him) certainly, your Lord is Oft-Forgiving, Most Merciful” [al-An‘aam 6:145]. 

Allah, may He be exalted, referred to
taqiyyah when He said (interpretation of the meaning):

“Let not the believers take the
disbelievers as Awliya (supporters, helpers, etc.) instead of the believers,
and whoever does that will never be helped by Allah in any way, except if
you indeed fear a danger from them. And Allah warns you against Himself (His
Punishment)”

[Aal ‘Imraan 3:28].

Here, Allah warns of His punishment, lest
the one who resorts to taqiyyah is tempted to persist in it. 

He should also pay attention to his
intention, and have the intention that he is only doing something haraam out
of necessity; he knows that it is haraam, but he is availing himself of the
concession granted by Allah. If he does it, taking the matter lightly and
thinking that there is nothing wrong with it, then he will fall into sin.

See: al-Mawsoo‘ah al-Fiqhiyyah,
191-200 

Dr. Naasir al-Qafaari said: 

In Islam, taqiyyah is usually used with
the disbelievers. Allah, may He be exalted, says (interpretation of the
meaning): “except if you indeed fear a danger from
them” [Aal ‘Imraan
3:28]. Ibn Jareer at-Tabari
said: The taqiyyah mentioned by Allah in this verse is that which is
resorted to in order to protect oneself from the disbelievers, not from
anyone else. Hence some of the early generations thought that there is no
taqiyyah after Allah caused Islam to prevail. Mu‘aadh ibn Jabal and Mujaahid
said: Taqiyyah was practised during the early days of Islam, before the
Muslims grew strong. But now Allah has caused the Muslims to prevail so
there is no need for taqiyyah. But the taqiyyah of the Shi‘ah is practised
with the Muslims, especially Ahl as-Sunnah, to the extent that they think
that the best of eras was the era of taqiyyah, as was stated by their shaykh
al-Mufeed. This may also be noted in the texts that they attribute to the
imams, because they regard Ahl as-Sunnah as being worse in disbelief than
the Jews and Christians, because the one who rejects the twelve Imams is
worse than one who rejects Prophethood. 

Taqiyyah – according to Ahl as-Sunnah – is
a concession to be used in times of necessity, hence Allah – may He be
glorified – exempted it from the principle that prohibits taking the
disbelievers as supporters and helpers. Allah, may He be glorified, says
(interpretation of the meaning):

“Let not the believers take the
disbelievers as Awliya (supporters, helpers, etc.) instead of the believers,
and whoever does that will never be helped by Allah in any way, except if
you indeed fear a danger from them. And Allah warns you against Himself (His
Punishment), and to Allah is the final return”

[Aal ‘Imraan 3:28]. 

Allah, may He be glorified, has forbidden
taking the disbelievers as supporters and helpers, and has issued a stern
warning concerning that, as He says, “and whoever does that will never be
helped by Allah in any way” i.e., and whoever transgresses the
prohibition issued by Allah in this regard, has severed his connection with
Allah. Then He, may He be glorified, says: “except if you indeed fear a
danger from them” i.e., except for those who, in some countries or at
some times, may fear their evil; in that case he may protect himself from
them by his outward words and actions, not by his inward beliefs and
intentions. 

The scholars are unanimously agreed that
taqiyyah is a concession that is allowed in the case of necessity. Ibn al-Mundhir
said: They are unanimously agreed that if a person is forced to say words of
disbelief, to the extent that he fears for his life, and he speaks words of
disbelief when his heart is content with faith, he is not to be deemed a
disbeliever. 

But the one who chooses to be steadfast in
this situation is better. Ibn Battaal said: And they are unanimously agreed
that the one who is forced to disbelieve but chooses to be killed will have
the greatest reward with Allah. 

But among the Shi‘ah, taqiyyah is
something else altogether. For them it is not a concession; rather it is one
of the pillars of their religion, like the prayer or greater.

End quote from Usool Madhhab ash-Shi‘ah
al-Imaamiyyah, 2/806-807. 

To sum up: 

There is a great difference between
taqiyyah in the religion of Allah and taqiyyah in the religion of the
Raafidis. In Islam it is a concession in cases of necessity, but for the
Raafidis it is nine-tenths of religion, and the one who has no taqiyyah has
no religion, according to them. 

Ibn Baabawayh (an Shi‘i scholar) said: Our
belief concerning taqiyyah is that it is obligatory, and the one who gives
it up is like one who gives up prayer.

End quote from al-I‘tiqaadaat, p.
114 

As-Saadiq (one of their Imams) said: If
you said that the one who gives up taqiyyah is like the one who gives up
prayer, you would be right. 

Jaami‘ al-Akhbaar,
p. 110; Bahaar al-Anwaar, 75/414, 412 

What a great difference there is between
the two!

And Allah knows best.