The fine-tuning of the universe for intelligent life has received a great deal of attention in recent
years, both in the philosophical and scientific literature. The claim is that in the space of
possible physical laws, parameters and initial conditions, the set that permits the evolution of
intelligent life is very small. I present here a review of the scientific literature, outlining cases
of fine-tuning in the classic works of Carter, Carr and Rees, and Barrow and Tipler, as well
as more recent work. To sharpen the discussion, the role of the antagonist will be played by
Victor Stenger’s recent book The Fallacy of Fine-Tuning: Why the Universe is Not Designed
for Us. Stenger claims that all known fine-tuning cases can be explained without the need
for a multiverse. Many of Stenger’s claims will be found to be highly problematic. We will
touch on such issues as the logical necessity of the laws of nature; objectivity, invariance and
symmetry; theoretical physics and possible universes; entropy in cosmology; cosmic inflation
and initial conditions; galaxy formation; the cosmological constant; stars and their formation;
the properties of elementary particles and their effect on chemistry and the macroscopic world;
the origin of mass; grand unified theories; and the dimensionality of space and time. I also
provide an assessment of the multiverse, noting the significant challenges that it must face. I
do not attempt to defend any conclusion based on the fine-tuning of the universe for intelligent
life. This paper can be viewed as a critique of Stenger’s book, or read independently.


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