Solipsism embeds a lot of un-articulated axioms in "I". The author's point is valid in that respect, that we need more axioms than just "I am", which is true,

Solipsism embeds a lot of un-articulated axioms in "I". The author's point is valid in that respect, that we need more axioms than just "I am", which is true, and they are all smuggled into our definition of what we mean by "I" and "am". Just take "I", and ask what am I? Or how am I? And so on. What is this "I" that I cannot doubt that I am? If we use dream physics, for example, we can answer a lot of the issues the author raised, which were, ultimately, mostly problems with the fact that "I" remains undefined. With dream physics, we can easily see that, given an "I" that works like a brain (or the abstract construct I have explicated to myself as "brain", whatevs), that it's very trivial to have other so-called "split" versions of ourselves, and events that seem to surprise us, scare us, or even cause us physical pain - though every single event in the dream is fabricated by the dreamer embedded in the dream.