The Theory of Intelligent Design as put forward by organizations like the Discovery Institute is, of course, nonsense.
But, what is not nonsensical, in my view, is the general concept of intelligent design as it might pertain to evolution.
First, there is a potential designer, and that is human beings, and we have demonstrated that we can change the environment, and those environmental changes result in
changes in not only non-human species, but also
humans as well.
Like it or not, humans are a "cause" of evolution and, at least, at the microbial level the rise of new species. But, can we be an "intelligent cause" that influences evolution in ways that enhance not only human life, but also non-human life?
So far, with the exception of a few domesticated species, parasites, and "disease" and pest organisms, our presence has had, on balance, a negative impact on most life on earth. Because of us, earth is less able to support life than it was before the rise of
Homo sapien, and in particular before
Homo sapien had acquired the use of energy beyond its own muscles.
Are we sufficiently intelligent to become an "intelligent designer" or the "intelligent cause" that the IDists are futilely searching for?
Personally, I don't think we are for basic Darwinian evolutionary reasons. We tend to make decisions that maximize our immediate personal well-being, as do all species, with little or no regard for longer term consequences or the effects on our and other species as a whole. Indeed, this is the essence of some libertarian thinkers, like Ayn Rand, and American proponents of individual liberty. It is raised to a moral "good" despite the fact that it rejects responsibility for any consequences perpetrated on others. This is pure Darwinian evolution in action.
Darwin's
Descent of Man could as aptly be titled the
Demise of Man. Intelligence of the human kind, I submit, is not conducive to our species' survival.