Why then would historians emphasize the importance of primary sources? If you rely on a progression of secondary sources over and over, you get serious misconceptions. Such as, for instance, your notion of the forms as being indicative of a descartian mind/body split. That simply isn't what Plato wrote.

So, as it turns out, not everyone can or should read primary sources. It's only for the select few. But those that do won't be dumber than those that only read secondary sources.