The Anthropic Principle is a modern development of the design argument. The argument is based on the fact that it is hugely unlikely that the universe could support intelligent life: and yet it does!
Here’s one account of how lucky we are to be alive:
Our atmosphere is composed of 78% nitrogen, 21% oxygen, and .03% carbon dioxide. If oxygen made up 23% or 19%, there could be no life on earth.
The cosmic factors at play when humans were just a twinkle in earth’s eye are astounding. Vary our current position 93 million miles from the sun just a million miles in either direction and life on earth could never have been. If our planet weren’t tilted 23.5 degrees on its axis, it would risk becoming “tidally locked,” meaning that one side of the planet would perennially face the sun and the other would look out into the cool dark of space—heating the first side and cooling the second until both were inhospitable to life. The earth tilts because 40% of its gravitational pull comes from the sun and 60% comes from the moon in a perfect balancing act. The moon happened into our orbit in the galactic equivalent of lassoing a randomly passing bull. Without this balance, earth wouldn’t have that quirky and scoliotic but fortuitously fertile lean.
Even the expansion of the universe itself follows a very particular rate. Just a tad slower and gravity would already have overcome the outward trajectory of celestial matter and sucked it back into a singularity—an infinitely tiny point, the kind which sparked the Big Bang. Just a smidge faster and the universe would now be a super-cooled wasteland of ice and rock.
Weak or Strong?
The Anthropic Principle can be weak or strong. Many definitions abound for these and you can spend quite a long time researching them if you like (I have and wouldn’t recommend it). But the basic point is this:
Weak Anthropic Principle (WAP): Intelligent life can evolve in the universe.
Strong Anthropic Principle (SAP): Intelligent life must occur in the universe.
The WAP is descriptive and impossible to refute, the SAP is prescriptive and based on…. not a lot. In fact, those who believe intelligent life must exist might already bringing a set of religious beliefs to the data. One way of viewing the two strands of the Anthropic Principle is this:
WAP: we depend on the universe
SAP: the universe depends on us!
F. R. Tennant
A key philosopher who developed the Anthropic Principle was F. R. Tennant, in his book Philosophical Theology (1930). His work can be best summarised using the handy acronym RUM.
R – RATIONALITY.
Tennant believes that the universe can be rationally understood. It is therefore rational to assume that there is a designer.
U – UNLIKELY.
As outlined above, the universe existing and supporting intelligent life is incredibly unlikely.
M – MAN
Tennant thinks that mankind is wonderful. We have heightened consciousness, ethics, art. Why would evolution require of us the delicacy of thought and feeling required to write opera, or the patience to learn to master our voices and the instruments? Indeed, sometimes we sacrifice ourselves for love, or for our principles. Why would this be the result of the brute machinations of a universe driven by chance? For Tennant, mankind itself was evidence of a divine creator.
Richard Swinburne
The ‘U’
The focus of the Anthropic Principle really is the ‘u’. Numerous philosophers have remarked upon the staggering unlikeliness of our universe. Those who oppose this viewpoint say, ‘well, of course it is unlikely, but we wouldn’t be here to talk about it if it hadn’t happened, so why all the fuss?’Richard Swinburne responds by giving the following example:
‘Suppose that a madman kidnaps a victim and shuts him in a room with a card-shuffling machine. The machine shuffles ten packs of cards simultaneously and then draws a card from each pack and exhibits all the ten cards. The kidnapper tells the victim that he will set the machine to work and it will show its first draw – unless the draw consists of an ace of hearts from each pack, the machine will automatically set off an explosion which will kill the victim so he will not see the cards the machine drew. The machine starts and to the relief of the victim he sees ten Aces of hearts. The victim thinks that this extraordinary fact needs an explanation in terms of the machine having been rigged in some way. The kidnapper now reappears and casts doubt on the suggestion. ‘IT IS HARDLY SURPRISING’ he says ‘THAT THE MACHINE DRAWS ONLY ACES OF HEARTS. YOU COULD NOT POSSIBLY SEE ANYTHING ELSE FOR YOU WOULD NOT BE HERE TO SEE ANYTHING AT ALL IF ANY OTHER CARD HAD BEEN DRAWN.’
But, Swinburne says, the victim is right and the kidnapper wrong. There IS something extraordinary about 10 aces of hearts being drawn – the fact that this is a necessary condition of anything being seen is not the point. The basic point that the existence of order is extraordinary is still valid.
This is supported by the respected astronomer Sir Fred Hoyle. Hoyle invented the term ‘Big Bang’, which he meant as an insult. Hoyle disagreed with the theory, and held other unpopular and subsequently disproven ideas. Hoyle writes that:
‘A component has evidently been missing from cosmological studies. The origin of the Universe, like the solution of the rubik cube, requires an intelligence… properties seem to run through the fabric of the natural world like a thread of happy accidents. But there are so many of these odd coincidences essential to life that some explanation seems required to account for them’ . Fred Hoyle The Intelligent Universe. P. 189
Criticism
There has been much criticism of the conclusion that intelligent life is the purpose of the universe – the SAP. Here is the revered essayist, novelist and wit Mark Twain’s view:
Man has been here 32,000 years. That it took a hundred million years to prepare the world for him is proof that that is what it was done for. I suppose it is. I dunno. If the Eiffel tower were now representing the world’s age, the skin of paint on the pinnacle-knob at its summit would represent man’s share of that age; & anybody would perceive that that skin was what the tower was built for. I reckon they would. I dunno.
– “Was the World Made for Man?” (1903)
A fascinating discussion, and rejection of the Anthropic Principle, is available below. The speakers are Richard Dawkins and Fr Coyne, both of whom are quotable authorities.
Thesis Eleven 