Analysing the Anthropic Arguments

Three positions need to be considered:

i) Combining the Weak Anthropic Principle with the Strong Anthropic Principle.

The Strong Anthropic Principle claims that the statement, ‘Observers exist’, in some sense constitutes a scientific explanation of the anthropic features of the cosmos. Two ways of interpreting this are possible.

It may be a claim that rational observers are the efficient cause of the universe. However, this would imply that time reversal is a reality on a cosmic scale and that in a very strong sense intelligent observers have (will have?) created their own reality.

Alternatively, the Strong Anthropic Principle may be read as a denial of the sufficiency of efficient causes as scientific explanations of certain physical problems. This implication of the SAP has caused some scientists and philosophers to reject it out of hand. However, it should be recalled that it was only with the rise of the mechanical model of the world that efficient causes were accepted as complete explanations in physics. Furthermore, the biological sciences have proved remarkably resistant to this view of scientific explanation.

ii) Combining the Weak Anthropic Principle with one of the Many-Universes Models

By contrast, the WAP does not claim to be explanatory: it is merely a selection effect. However, like the SAP, it has a covert content. It is pointless unless it is used in conjunction with one of the Many-Universes Models.

Thus it functions as a way of commending to the scientific establishment certain speculative cosmologies which have so far failed to convince when restricted to more conventional forms of scientific argumentation.

iii) Combining the Weak Anthropic Principle with an Anthropic Design Argument

It is very tempting for a theist to make the move which Paul Davies makes when he writes:

Is it easier to believe in a cosmic designer than the multiplicity of universes necessary for the weak anthropic principle to work? ... Perhaps future developments in science will lead to more direct evidence for other universes, but until then, the seemingly miraculous concurrence of numerical values that nature has assigned to her fundamental constants must remain the most compelling evidence for an element of cosmic design.

or to assent to the ‘Moderate Anthropic Principle’ proposed by John Polkinghorne (see anthropic design arguments).

However, design arguments based on these features make certain assumptions that may make one cautious about placing too much reliance on them.

To begin with, they assume that the anthropic features of the cosmos are, in themselves, improbable. However, quite apart from the difficulties of assigning probabilities to these parameters, such an assumption is far from proven. It is conceivable that future developments in physics might render these very features quasi-necessary. In such a situation, this entire class of design argument would collapse. There is a hint of the God of the gaps about such arguments: the universe appears to be a highly improbable structure: we cannot give a rational explanation of these cosmological features: therefore, they constitute evidence of an intelligent designer. And, like the God of the gaps, the role of this deity shrinks with the expansion of scientific understanding.

For a recent assessment of the anthropic arguments see M.W.Worthing’s God, Creation and Contemporary Physics.

Email link | Feedback | Contributed by: Dr. Christopher Southgate
Source: God, Humanity and the Cosmos  (T&T Clark, 1999)