 According to the standard reading, in the "Philosophical Investigations" Wittgenstein repudiates many of his own earlier views, expressed in the "Tractatus Logico-Philosophicus".The "Tractatus", as Bertrand Russell saw it (though Wittgenstein took strong exception to Russell's reading), had been an attempt to set out a logically perfect language, building on Russell's own work.In the years between the two works Wittgenstein came to reject the idea that underpinned logical atomism, that there were ultimate "simples" from which a language should, or even could, be constructed.