Thomas Aquinas's Theologica Summary

In his Summa Theologica number seventeen, article two, Aquinas is trying to answer the question of whether there is falsity in the senses and, if there is, how it exists. He concludes that falsity does exist in the senses in the way that the senses can misjudge objects. Aquinas maintains that the senses can perceive the likeness of an object in one of three ways. The first is by the color of the object and other proper qualities which occur in only one sense. The second is by the common qualities of shape and size which can be validated by more than one of the senses. Finally, the third occurs accidently and not of its own nature. He follows that by stating the premises for his argument. Aquinas’s first premise is the sense gains false knowledge