Praise be to Allah.

Studying these two subjects (psychology and law) involves studying matters that are explained and discussed in a manner that is contrary to Islamic teachings. This is something clear and makes sense, because the law in the view of non-Muslims is a counterpart to sharee‘ah for the Muslims, and psychology is a counterpart to morals and manners, asceticism, softening the heart with fear of Allah, purification of the soul, good conduct and discipline. Because the people do not follow the religion of Islam, no matter what their religion and view, it is logical to say that they base their laws and morals on something other than the law of Allah, may He be exalted, that He has chosen for His slaves. Rather they base all of that on their experience, reason, feelings or customs, or on other things that they believe in, and they regard it as the system to be followed. 

As that is the case, studying these two subjects, and similar subjects – such as philosophy and non-Islamic economics – is not permissible for the Muslim if the aim is to benefit from all of that without discretion, and to believe what they contain of misguidance and put it into practice, take it as a way of life and derive from it rules to follow. All goodness is in following the guidance and light that the Prophet brought. 

Allah, may He be exalted, says (interpretation of the meaning):

“O mankind! Verily, there has come to you a convincing proof (Prophet Muhammad (blessings and peace of Allah be upon him)) from your Lord, and We sent down to you a manifest light (this Quran)”

[an-Nisa’ 4:174]

“Indeed, there has come to you from Allah a light (Prophet Muhammad (blessings and peace of Allah be upon him)) and a plain Book (this Quran)”

[al-Maa’idah 5:15]

“Say: O you mankind! Now truth (i.e. the Quran and Prophet Muhammad (blessings and peace of Allah be upon him)), has come to you from your Lord. So whosoever receives guidance, he does so for the good of his own self, and whosoever goes astray, he does so to his own loss, and I am not (set) over you as a Wakeel (disposer of affairs to oblige you for guidance)”

[Yoonus 10:108]. 

The Prophet (blessings and peace of Allah be upon him) forbade the Muslims to read the books of the People of the Book and others. He (blessings and peace of Allah be upon him) got angry when he saw in the hand of ‘Umar (may Allah be pleased with him) one of the books of the Jews, as it was narrated in Musnad Ahmad (14623): ‘Umar ibn al-Khattaab came to the Prophet (blessings and peace of Allah be upon him) with books that he had got from some of the People of the Book. The Prophet (blessings and peace of Allah be upon it) saw it and got angry. He said: “Are you confused about it, O son of al-Khattaab? By the One in Whose hand is my soul, I have brought it (i.e., the message of Islam) to you clean and pure. Do not ask them about anything, lest they tell you something true and you disbelieve in it, or they tell you something false and you believe in it. By the One in Whose hand is my soul, if Moosa (blessings and peace of Allah be upon him) were alive, he would have no option but to follow me.”

[Classed as saheeh by al-Albaani in al-Irwa’, 6/34] 

The prohibition is emphasised when it comes to learning and studying these branches of knowledge, if the Muslim does not have sufficient knowledge to recognise what is evil in these subjects and distinguish between it and what they contain of goodness, for if that is the case he will inevitably be affected by some of their evil. We have seen this in many of the Muslims who studied these subjects in the last two centuries, who were called the “pioneers of enlightenment” in the Arab world; they caused confusion and were the first to call for sharee‘ah to be abolished from Muslim countries and they replaced it with Roman and French law. They tried and worked hard to give Muslim societies a western flavour in all fields of life, and they branded those Muslims who adhered to their religion as backward, stagnant, fundamentalists, lovers of darkness and other such words that stemmed from the European environment. 

But if a Muslim has strong faith and is mature in his thinking, so that there is no fear of a man of his calibre becoming confused by the specious arguments that are present in these subjects, then it is permissible for him to study them. In fact it may be obligatory in the case of particular individuals, so that they may follow the latest trends in the theories, ideas and philosophies of the non-Muslims, and refute them and explain what they contain of misguidance, if they find their way to the Muslim lands in the guise of literature, art, culture, academic curricula, economics, social studies, and systems of rulings and management. 

The importance of the matter becomes more urgent if there is an instruction to do so from the Muslim ruler who is sincere to his ummah, as the Prophet (blessings and peace of Allah be upon him) instructed Zayd ibn Thaabit to learn the language of the Jews. 

Al-Bukhaari mentioned that in a chapter in his Saheeh (6/2631) in which he said: Chapter on translating for rulers; is it permissible to have one translator? Khaarijah ibn Zayd ibn Thaabit narrated from Zayd ibn Thaabit that the Prophet (blessings and peace of Allah be upon him) instructed him to learn the language of the Jews, until I wrote letters for the Prophet (blessings and peace of Allah be upon him) and I read to him their letters if they wrote to him.

Narrated and classed as saheeh by at-Tirmidhi (no. 2639); classed as saheeh by al-Albaani in al-Mishkaat (4659) 

A similar question was asked of the Standing committee for Issuing Fatwas and they replied as follows: 

It is not permissible to learn man-made laws in order to apply them, so long as they are contrary to the laws of Allah. But it is permissible to study law and learn it in order to explain its flaws and how it has deviated from the right path, and to highlight the justice and fairness that there is in Islam, how sound it is and how it is sufficient for people’s interests. It is not permissible for a Muslim to study philosophy, man-made laws, and the like, if he is not able to distinguish between what is right and what is wrong in them, lest he become confused and deviate from the straight path. But that is permissible for one who is able to understand it after having studied the Qur’an and Sunnah, so that he is able to distinguish the bad from the good in these subjects, so that he will be able to confirm the truth and nullify falsehood, so long as that will not distract him from more important duties. Thus it is known that it is not permissible to teach these subjects in schools and universities, and it should only be for the elite who are qualified for that, so that they may undertake their Islamic duty of supporting the truth and refuting falsehood.

Fataawa al-Lajnah ad-Daa’imah (14/232-233) 

Our advice to our brother is to examine his own situation: does he meet the conditions referred to above, namely knowledge of sound belief (‘aqeedah) and adherence to it, mature thinking that can distinguish between truth and falsehood, the ability to refute specious arguments and misguidance on the basis of sound evidence, and sincerity towards Islam. If, after examining himself, he feels that he meets these conditions, then he may go ahead and study these two subjects, after praying to Allah, may He be exalted, for guidance in making that decision (istikhaarah). Otherwise it is better for him to forget about that and study some other, purely scientific, subject. 

And he should remember that whoever gives up something for the sake of Allah, Allah will replace it with something better than it. 

We ask Allah to help you and guide you to that which will benefit you in religious and worldly terms. 

And Allah knows best.