They claim that there is no Creator. Some have even said that a human is just another animal, so it should come as no surprise when a person acts in an animalistic fashion.
فَكَثِيرُونَ مِنْ مُؤَيِّدِيهَا يُصَرِّحُونَ بِأَنَّ ٱلْحَيَاةَ نَشَأَتْ دُونَ أَيِّ مُصَمِّمٍ ذَكِيٍّ ،‏ مُنْكِرِينَ وُجُودَ خَالِقٍ .‏