Collins’ argument

1. The best unified explanation of (a) fine-tuning for life, (b) beauty and (c) discoverability of the laws of nature is a transcendent, intelligent designer.
2. The best unified explanation is probably true.
3. So, probably, there is a transcendent, intelligent designer.

The likelihood principle

If we have two hypotheses H₁ and H₂ and a piece of evidence E is more likely on H₁ than on H₂, then E is evidence for H₁.

Example:

• Secret die roll
• H₁=even
• H₂=odd
• Told the answer is less than four
• Probability of <4 on even = 1/3 (2 is the only <4 option out of 2, 4, 6).
• Probability of <4 on odd = 2/3 (1 and 3 are both <4 options out of 1, 3, 5).
• So, we have evidential boost for H₂.

Objections

• Grand Unified Theory
• Many Universes