أَنَّ ذَلِكَ لِفَسَادِ النَّظَرِ
That disagreement can result from defective reasoning.
فَلَا يُنَافِي كَوْنَ النَّظَرِ الصَّحِيحِ مِنَ الْعَقْلِ مُفِيدًا لِلْعِلْمِ
Therefore, disagreement does not contradict the proposition that sound reasoning produces knowledge.
Two people can reach different answers in arithmetic because one miscalculates; that does not invalidate arithmetic itself. Equally, disagreement in theology does not disprove every well-formed argument. It also does not prove a particular disputed conclusion: its premises and reasoning still require examination.