One fairly common thread among people who argue that life must be intelligently designed is that, whether it is evolution or something else, natural mechanisms are not adequate enough to explain the origin and complexity of biological organisms. The main problem with this line of reasoning is that it is premised on the (alleged) fact that we do not, currently, completely understand something within a naturalistic framework – not that we cannot understand that same something within a naturalistic framework. The flaw, of course, is that we may one day figure it out – at least to a satisfactory level – thereby invalidating the conclusion.

Consider the following argument as put forward by Isaac Newton himself concerning the order and arrangement of the solar system:

To your second query I answer, that the motions, which the planets now have, could not spring from any natural cause alone, but were impressed by an intelligent agent…it is plain that there is no natural cause which could determine all hte planets, both primary and secondary, to move the same way and in the same plane, without any considerable variation: this must have been the effect of counsel. Nor is there any natural cause which could give the planets those just degrees of velocity, in proportion to their distances from the sun, and other central bodies, which were requisite to make them move in such concentric orbs about those bodies…To make this system, therefore, with all its motions, required a cause which understood, and compared together the quantities of matter in the several bodies of the sun and planets, and the gravitating powers resulting from thence; the several distances of the primary planets from the sun, and of the secondary ones from Saturn, Jupiter, and the earth; and the velocities, with which these planets could revolve about those quantities of matter in the central bodies; and to compare and adjust all these things together in so great a variety of bodies, argue that cause to be not blind or fortuitous, but very well skilled in mechanics and geometery. (Quoted in E. A. Burtt, The Metaphysical Foundations of Modern Science, pgs. 289-290)

Of course, nobody makes this kind of argument in favor of Intelligent Design any more because we know how this is possible without recourse to “an intelligent agent.” How long from now will it be until people look back at similar arguments concerning the origins of life and evolution today as another historical curiosity?