Cartesian Possibility Of Illusion

Putnam begins his journey of semantic refutation, with the natural first step since Socrates and the Sophists. That of systematically breaking down the opposing argument, the central thesis of his writing. That opposition being the skeptical argument, of: 1) If I know that P, then I know that I am not a BIV 2) I don’t know that I am not a BIV 3) Thus, I do not know P.
This is akin to the question posed by Descartes, and the inability to legitimately verify that our own experience isn’t an individual illusion/hallucination/delusion, despite our ability to verify its exist-ent ergo “I think therefore I am”. It is the table on which most every skeptic rests his hat in this re-gard.

A simple argument of logic combined with the doubt of the
However I don’t feel that Putnam successfully argues against the Cartesian possibility of illusion, as his own theorem would say that a being is not able to understand the ex-istence in which it lives in, only that beneath it, such as the Mad Scientists to the brains in the Vat. Yet even the scientist is unable to comprehend and understand the Universe or plane in which he exists by the acceptance of said proof. He would not be able to verify that the other Mad Scientists are real in the metaphysical sense, only his own existence. This I feel is the same problem that Put-nam runs into, in that, his semantical argument is structurally sound, it makes a logical argument against the haunting specter of Descartes, and the nightmare of uncertainty. How the idea of the mass illusion is impossible, yet Putnam accepts that “possibility” still remains. Because we have no direct link to each others minds and thoughts, we are still stuck in the limbo of doubt metaphysical-ly. Regardless of how mathematicians and philosophers wish to posture their answers, the noble ass arrives most beautifully and his name is conviction. The issue remains that there is no actual meth-od to verify that if two individuals see the same tree, it is referred to in the same manner. There are so many different possibilities because of the addition of two individuals rather than one. Whether that person is our friend, who perhaps doesn’t have the same verbal skills and ability to articulate, will not describe the tree in the same manner as you. Or an individual from another country, lets say Russia. If that individual is not able to find a common ground of language, the issue becomes translation and the distinctions between languages and the meanings they are trying to