Reason and Imagination of C. Darwin

             Darwin’s argument is well reasoned and he provides very good evidence, but, as he admits, the evidence is limited by the confounding factor of the missing links between species.  In discussing the fossil record Darwin states, “ the geological record is imperfect all will admit; but that it is imperfect to the degree I require, few with be inclined to admit”.(383).  If this claim existed on its own as Darwin’s main syllogism it would be very had for Darwin to have made it stand, but the complexity of Darwin’s argument and his ability to fill inference with imagination that lends character and validity to his argument.  The previous argument stated more formally and in a less convoluted way it could read:

If we had a full fossil record then we would be able to see and entire linage of species

If we had an either lineage to species to view then we could show strong evidence for evolution

We do not have a full fossil record

Therefore we do not have strong evidence for evolution.

            Darwin’s mastery in rhetorical and narrative rescue him from this possible failure of reason.  Rather than trying to argue his point further on this ground Darwin takes a Dickensian turn and leave this narrative for a discussion of domestic species.  Darwin state that “under domestication we see much variability…man does not actually produce this variability; he only unintentionally exposes organic being to new conditions of life, and then nature acts on the organization and causes variability”(383).  This new argument, that we have observed variation of species, and this variation is the natural state not something inflicted by man is of great importance to the first argument.

            Darwin asks of the reader that they imagine how this variation that is observed can be used to interpret the fossil record, and his argument now becomes

We know that domesticated animals vary between generations

This variation is caused by nature not by man

If we had even a partial fossil record and it showed similar variation we would have strong evidence that that evolution had been taking place in the past

We do have a partial fossil record and it does show similar variation to that which we have observed

Therefore we do have strong evidence for evolution

The logical force of Darwin’s argument comes from the fact that he does not try to have any one piece of evidence do more than it can, and he often choses to lessen the force that his puts behind and individual piece of evidence and his diligence in insuring that each piece of evidence that he gives is backed by yet another. 

However reasoned and principled C. Darwin’s argument is he subtly coopts the imagination of the reader to follow him through his story and in this way is even more convincing. In the opening paragraph of chapter XIV Darwin states when discussing how anything as magnificent as human intelligence could have evolved

“ Nevertheless, this difficulty though appearing to our imagination insuperably great, cannot be considered real if we admit the following propositions, namely, - that the gradations in the perfection of any organ or instinct, which we may consider, either do now exist od could have existed, each good of its kinds – that all organs and instincts are in ever so slight a degree variable, - and, lastly, that there is a struggle for existence leading to the preservation of each profitable deviation of structure or instinct. The truth of theses propositions cannot, I think, be disputed.”(379).

In this passage Darwin acknowledges that no mater how much he bases his argument on reason, and his reason is good, the imagination of the reader will be a greater influence on weather or not they believe it, and it is their imagination that allows them to combine the arguments that he makes.  This combination being the most important and masterful portion of his argument in favor of evolution.