The term Waswas (in Arabic وسوس) in Islam literally refers to "whispers (usually from Shaitan [Satan])". However, the term is usually used to refer to doubts and temptations. It is commonly believed that Satan and his minions tempt Muslims to sin and weaken their faith in Islam through doubt. When Muslims have negative thoughts about Islam, or thoughts that go against the teachings of Islam this is usually regarded as waswas (or waswasa). Critics see this as a way to dismiss concerns around Islam and excuse human and biological natural drive.
Waswas in the Qur'an
The Arabic word وسوس (waswas) in various forms appears five times in the Qur'an.
The first two refer to the story of Adam and Eve. The fa- prefix means "but" or "then".
In one instance the Quran says the soul whispers. The tu- simply indicates present tense, 3rd person, feminine, singular verb.
Two times in a chapter 114. The al- indicates definite article (before a noun). The yu- indicates present tense, 3rd person, singular, masculine verb.
Tafsir Al-Jalalayn says that the "whisperer" in 114:4 is Satan:
114:1 Say: I seek refuge in the Lord of men,
114:2 The King of men,
114:3 The god of men,
114:4 From the evil of the retreating whisperer (ٱلْوَسْوَاسِ, al-waswasi)
114:5 Who whispers (يُوَسْوِسُ, yuwaswisu) into the hearts of men,
114:6 From among the jinn and the men.
It was narrated from 'Abdullah bin Mughaffal that the Prophet (ﷺ) said:"None of you should urinate in the place where he bathes, for most Waswas (devilish whispers)  come from that."  I.e., with regard to whether the urine has soiled his body or not.
"Alqamah prayed five (rak'ahs) and was told about that. He said: 'Did I really do that?' I nodded yes. He said: 'What about you, O odd-eyed one?' I said: 'Yes'. So he prostrated twice, then he narrated to us from 'Abdullah that the Prophet (ﷺ) prayed five (rak'ahs), and the people whispered to one another, then they said to him: 'Has something been added the prayer?' He said: 'No.' So they told him, and he turned around and prostrated twice, then he said: 'I am only human; I forget as you forget.'"
It is narrated on the authority of Abu Huraira that some people from amongst the Companions of the Apostle (ﷺ) came to him and said:Verily we perceive in our minds that which every one of us considers it too grave to express. He (the Holy Prophet) said: Do you really perceive it? They said: Yes. Upon this he remarked: That is the faith manifest.
Association with science denial
Doubt is a cornerstone of the scientific method. However, the concept of waswas attributed doubt to evil supernatural forces.
There are many instances of believers trying to "cure" themselves from waswas . The basic treatment method is ruqya - exorcism. Verses from the Qur'an are recited on the "posessed" Muslim. There is also a possibility of self-ruqya , where Muslim tries to get rid of waswas by praying and reading the Qur'an (and other practices).
The waswas-avoiding behavior could probably be best described, in a secular way, as a psychological repression. A Muslim represses his "bad" thoughts. He pushes them out of his consciousness, into the unconscious mind. From the unconscious mind, the repressed thoughts might express themselves in dreams or as inner voices.
The therapy for psychological repression is basically the opposite of what "Islamic therapy" does. In Freud's psychotherapy, the psychotherapist re-introduces the repressed thoughts back into the conscious mind . The conscious mind then learns to live with the previously-repressed thoughts and so there is no more repression. While the Islamic treatment of waswas is trying to repress the "bad" thoughts so much that they become silent. Which is not possible, because repressed thoughts don't disappear. They only hide in the unconscious mind and there they still affect a person's behavior and cause psychological problems.
- 114:1 Say: I seek refuge in the Lord of men, 114:2 The King of men, 114:3 The god of men, 114:4 From the evil of the retreating '''whisperer''' (ٱلْوَسْوَاسِ, ''al-waswasi'') 114:5 Who '''whispers''' (يُوَسْوِسُ, ''yuwaswisu'') into the hearts of men, 114:6 From among the jinn and the men. Quran 114:1-6
- Just Google "waswas".
- Freud, Five Lectures p. 35