So philosophical thought, law and (association, ie. social) contract are illegal in an anarchist society?
What is your authority for saying it is illegal in the anarchist society?
You are truly deluded.

Follow what has been sent down to you by your Lord, and follow
no masters other than Him/Sunnatullah/Law of Nature. How seldom do you remember! (7:3)
“
Anarchy is law and freedom without force.
Despotism is law and force without freedom.
Barbarism force without freedom and law.
Republicanism is force with freedom and law.”
― Immanuel Kant, Anthropology from a Pragmatic Point of View
advocates stateless societies based on free and voluntary associations. Anarchists seek a system based on the abolishment of all unjustified, coercitive hierarchy and the creation of system of direct democracy and worker cooperatives; Wikpedia
Private OffenceThere is no compulsion where the deen is concerned. Right guidance has become clearly distinct from error. Anyone who rejects false gods and has iman in Allah has grasped the Firmest Handhold, which will never give way. Allah is All-Hearing, All-Knowing. (2:256)
If your Lord had willed, all the people on the earth would have had iman. Do you think you can force people to be muminun? No self can have iman except with Allah´s permission. He places a blight on those who do not use their intellect. (10:99-100)
Say: ´It is the truth from your Lord; so let whoever wishes have iman and whoever wishes be kafir.´ (18:29)
So call and go straight as you have been ordered to. Do not follow their whims and desires but say, ´I have iman in a Book sent down by Allah and I am ordered to be just between you. Allah is our Lord and your Lord. We have our actions and you have your actions. There is no debate between us and you. Allah will gather us all together. He is our final destination.´ (42:15)
Only argue with the People of the Book in the kindest way — except in the case of those of them who do wrong — saying, ´We have iman in what has been sent down to us and what was sent down to you. Our God and your God are one and we submit to Him.´ (29:46)
It is not for you to guide them. God guides whomever He wills (2:272)
You surely cannot guide whoever you like, but it is Allah Who guides whoever He wills, and He knows best who are fit to be guided. (28:56)
Your only duty is to deliver the message clearly (16:82, 14:4, 4:82)The form of punishment in the anarchist society (Intentional Community)If they had had iman in Allah and the Messenger and what has been sent down to him, they would not have taken them as friends. But most of them are deviators. (5:81, 3:28, Chapter 60 and 48:29)
You have an excellent example in Ibrahim and those with him, when they said to their people, ´We wash our hands of you and all that you serve apart from Allah/ Sunnatullah/ Law of Nature/ Moral Universalism, and we reject you. Between us and you there will be enmity and hatred for ever unless and until you have iman in
Allah/ Sunnatullah/ Law of Nature/ Moral Universalism alone.´ Except for Ibrahim´s words to his father: ´I will ask forgiveness for you but I have no power to help you in any way against Allah.´ ´Our Lord, we have put our trust in You. and have made tawba to You. You are our final destination. (60:4)
Allah does not forbid you from being good to those who have not fought you in the deen or driven you from your homes, or from being just towards them. Allah loves those who are just. Allah merely forbids you from taking as friends those who have fought you in the deen and driven you from your homes and who supported your expulsion. Any who take them as friends are wrongdoers. (60:8-9)
Intentional Community
Mankind! We created you from a male and female, and made you into peoples and tribes so that you might come to know each other. The noblest among you in Allah´s sight is the one with the most taqwa. Allah is All-Knowing, All-Aware. (49:13)
Public Offence (Criminal Law)Permission to fight is given to those who are fought against because they have been wronged — truly Allah has the power to come to their support — those who were expelled from their homes without any right, merely for saying, ´Our Lord is Allah´ (if Allah had not driven some people back by means of others, monasteries, churches, synagogues and mosques, where Allah´s name is mentioned much, would have been pulled down and destroyed. Allah will certainly help those who help Him — Allah is All-Strong, Almighty), (22:39-40)
What reason could you have for not fighting in the Way of Allah — for those men, women and children who are oppressed and say, ´Our Lord, take us out of this city whose inhabitants are wrongdoers!
Give us a protector from You! Give us a helper from You!´? Those who have iman fight in the Way of Allah. Those who are kafir fight in the way of false gods. So fight the friends of Shaytan! Shaytan´s scheming is always feeble. (4:75-76)