Slavery was an established and applied system among the nations before Islam and it was free of any restrictions. Islam's struggle against slavery aimed at changing the perspective and mentality of the whole society in such a way that slaves, after their emancipation, would become full and effective members of society without the need to resort to demonstrations, strikes, civil disobedience, or even ethnic revolutions. The objective of Islam was to get rid of this abominable system as soon as possible through peaceful methods.
As a matter of fact, uncovering the head is complete and utter backwardness. Is there any further backwardness beyond the time of Adam; Allah ensured for Adam and his wife concealment and clothing since the time they were created and made to live in Paradise.
Although we could see the rainbow and the mirage, yet they do not actually exist. Moreover, we believe in the existence of gravity without seeing it just because its existence was proven by the material science.
