George Smith is a rather hard individual to come across with respect to biographical information. However, from what can be gathered, George H. Smith was born in February of 1949 into a military family. He was born in Japan, and lived in many other foreign countries throughout his childhood, while finally moving to Arizona to attend the university with an incomplete degree in Philosophy. Later settling in Los Angeles, Smith then began his affiliation with the Libertarian movement and published many articles on the matter (these include Reason, Libertarian Review, and Journal of Libertarian Studies). In regards to Smith’s libertarian perspective, Michael Martin writes in his review of Smith’s book, Atheism: The Case Against God :
He has. . . been greatly influenced by Ayn Rand and Nathaniel Branden (Rand and Branden are cited and quoted more frequently in the book than anyone else) and on the back cover Smith is billed as a student of the libertarian point of view and co-editor of a libertarian periodical. However, Smith’s libertarian views are absent from the present work and his quotations from Rand and Branden have nothing to do with their political views. 
Gordon Stein (Ph.D.) in his book An Anthology of Atheism and Rationalism  writes in high regards to Smith’s atheological volume (see p. 46), which is the motivation for our considerations of Smith’s claims here.
The Onus Probandi
Onus Probandi is the Latin phrase for ‘burden of proof’. An application of this concept can be found in one of Smith’s earlier works:
The atheist is not obligated to answer arbitrary assertions, unproven assumptions and sloppy generalizations concerning the nature and consequences of the atheistic position. Atheism is the absence of belief in a god, nothing more. If the theist wishes to draw monumental implications from this lack of belief, he must argue for his claims… It is the atheist who demands proof from the theist, not vice-versa. 
George Smith suggests that this ‘onus probandi’ principle ‘falls on the person who affirms the truth of a proposition, such as ‘God exists.’ If the theist claims to know that God exists, then we have the cognitive right – indeed, the responsibility – to ask this person how he acquired this knowledge and why we should take him seriously” . This in an of itself is not argument against theism, or even for atheism, but shows that if the theist fails to meet his burden of proof, then “atheism is left standing by default as the only rational alternative” .
The reason for this (as I think Smith rightly points out) is that one who affirms a claim, or presents himself to have positive belief on some proposition x, then that person is expected to present evidence for the truth of that claim. An important consideration of evaluating and analyzing knowledge claims is to see whether or not there are any good reasons for holding them. For instance, it is very well possible that the entire universe and all of our past memories were encoded into our brains just 5 minutes ago with the deception that the universe is actually billions and billions of years old.
Of course, it is logically possibly that this is the case, but we have no good reasons to suggest that it is true because we could never falsify it. Smith suggests that this is the problem with the theist – the one who does have a positive position in regards to a claim (‘God does exist’) while the atheist (by supposed definition) does not. Annie Besant once wrote in her short essay, “Why I Do Not Believe in God” (1887) that
the rational attitude of the human mind is not that of a boundless credulity, accepting every statement as true until it has been proved to be false, but is that of a suspension of judgement on every statement which, though not obviously false, is not supported evidence, and of an absolute rejection of a statement self-contradictory in terms, or incompatible with truths already demonstrated .
However, Besant goes on to say that ‘the Atheist makes no general denial of the existence of God’ (Stein: p. 31), but rather that the ‘Atheist’s denial of the Gods begins only when these Gods are defined or described’ (Stein: p. 31). Once this God is defined however (according to Besant) to have an infinite personality, be infinite in goodness and infinite in existence, he exists just as square triangles exist (satirically of course, suggesting that He does not). This is a similar position to Smith’s. He claims that the atheist makes no claims in affirmation to God’s negative existence (Smith 1979: 16-18).
This in light of his adherence to implicit and critical atheism (see Smith 1979: 17). Critical atheism of course being, “I do not believe in the existence of a god or supernatural being” (Smith 1979: 17). Yet, the epistemological bumper sticker still rests with this statement – i.e., it is only often stated when the theist fails to provide any evidence in favor of his claims for God’s existence. Therefore, according to Smith, “the critique of theism is the defense of atheism.”
My reason for analyzing Smith for his definition and not so much his arguments (see Smith 1979: 29, arguing against the ‘Concept of God’) is because this is often the mistake found in the literature regarding what is expected of atheism to establish in regards to its own declarative worldview (although we have supposedly seen that it isn’t actually ‘declarative’). Later throughout, we will examine other deductive arguments arguing against theism and the coherence of the concept of God.
-  George H. Smith, Atheism: The Case Against God (Promotheus Books: 1979)
-  Michael Martin, http://www.infidels.org/library/modern/michael_martin/review-smith.html
-  Gordon Stein, An Anthology of Atheism and Rationalism (Promotheus Books: 1980)
-  George Smith, http://www.infidels.org/library/modern/george_smith/defending.html
-  Smith 1979: p. 27
-  George H. Smith, Why Atheism? (2000) p. 31
-  Smith 2000: p. 31
-  Stein, pp. 30-31