Even the Indians and their philosophers—though they are polytheists who worship idols—cannot plausibly be thought to deny what existed before their own birth. None of them rejects the existence of lands, rivers, mountains, or houses he has never seen, nor does he deny the existence of every human being or beast he has not personally observed. No child of Adam behaves in that manner. All mankind agrees that what they witness they know by direct sight, and that what lies beyond their sight they know through transmitted reports; it is therefore inconceivable that any group would unite in rejecting reports altogether.

Yet sophistry may befall certain sects and some individuals with respect to particular fields of knowledge, for the maladies of the heart are like the maladies of the body: just as there is no nation or person who suffers every disease, so there is no one who is ignorant of everything, corrupt in every belief, and misguided in every intention. Rather, some people are afflicted with certain illnesses, and indeed there are communities in which specific diseases are widespread. Such patients gain no benefit from natural foods; they require treatment and medicines suited to their constitution.

Similarly, when someone is afflicted by sophistry and his innate disposition is diseased in certain areas of knowledge, one does not address him with purely theoretical proofs; instead, a form of therapy and medication is employed. The very definitions and arguments that compel him to examine and reflect—once he grasps them as a preliminary—may well remove