“Knowledge based on the senses is therefore a subjective judgment, an ever-varying opinion without any absolute foundation. True knowledge, by contrast, is possible only from a direct apprehension of the transcendent Forms, which are eternal and beyond the shifting confusion and imperfection of the physical plane. Knowledge derived from the senses is merely opinion and is fallible by any nonrelative standard. Only knowledge derived directly from the Ideas is infallible and can be justifiably called real knowledge.”