وَالْحِسُّ قَدْ يَغْلَطُ كَثِيرًا
The senses may frequently err.
The objection begins from a real phenomenon: visual or gustatory experience can be distorted under certain conditions. It then infers that sensory knowledge as a whole cannot be certain.
The first observation is sound; the global conclusion requires a further argument. If a particular cause distorts vision, not every observation follows under that same distorting condition.
“Some sensory judgments are mistaken” is a particular claim, whereas “all sensory judgments are mistaken” is universal. The first does not establish the second. This shift in scope is the central point to examine when evaluating the objection.