Bill also evaluates Rand’s argument to the effect that “to grasp the axiom that existence exists, means to grasp the fact that nature, i.e., the universe as a whole, cannot be created or annihilated, that it cannot come into or go out of existence.” He sees in this an inadvertent echo of modal Spinozism, and not implausibly. But to me it is even more reminiscent of the even more extreme metaphysics of Parmenides . . . .
The Parmenides connection is very interesting. When I asked Harry Binswanger why he thinks that the existence of nature is logically necessary, he replied,
Well, the first part is axiomatic: "existence exists." What makes that logically necessary? The fact that "existence doesn't exist" is a contradiction. "What is, is; what is not, is not" Parmenides wisely said.
Ernst Haeckel said that ontogeny recapitulates phylogeny, that the development of the individual recapitulates the development of the species. Whether or not this is true in biology, it is often true with amateur philosophers: these members of the Philo-phylum have a tendency to 'reinvent the wheel' while at the same time failing to appreciate the defects of their primitive reinvented 'wheel.'
Now you might want to dismiss what I just wrote as a cheapshot, but you will see that it is not if you study what I say here and here and here. There is no 'Rand-bashing' here, contra what some opine; there is the careful and critical examination of ideas. That is part of what philosophy is.