The great astrophysicist Fred Hoyle, who made important discoveries about the development of stars and how chemical elements are produced within them, was one of the first modern intelligent design theorists. Hoyle, who wasn't a creationist, believed in "evolution" in the wider sense of the word: descent of new species from older, different ones, over long time periods. But he proposed, on the basis of the scientific evidence, that some sort of intelligence had played a role in the origin of all species. As a long-time materialist and atheist, he preferred to arbitrarily assume that the intelligence involved arose naturally in the universe, by some sort of physical laws: that it was a "cosmic intelligence." Hoyle influenced many other intelligent design theorists, beginning in the 1980's. Most of them saw no reason to assume that the intelligence or intelligences involved must have arisen naturally. While I also see no reason to think or assume that the designing intelligence involved in ID theory arose naturally, Hoyle does show that such a natural designing intelligence is conceivable, and is available for those who don't want to accept anything supernatural.
In his book Cosmic Life-Force, published in 1988 and 1990 and co-authored by his colleague Chandra Wickramasinghe, Hoyle detailed his views on intelligent design. Chapter 10 of the book is entitled "The concept of a Creator." By a Creator, Hoyle meant an intelligence that designed some aspects of life. The authors wrote:
"The alternative to assembly of life by random, mindless processes is assembly through the intervention of some type of cosmic intelligence. Such a concept would be rejected out of hand by most scientists, although there is no rational argument for such a rejection. With our present knowledge, chemists and biochemists could now perform what even ten years ago would heve been thought impossible feats of genetic engineering. They could, for instance, splice bits of genes from one system to another, and work out, albeit in a limited way, the consequences of such splicings. It would not need to great a measure of extrapolation, or too great a license of imagination, to say that a cosmic intelligence that emerged naturally in the Universe may have designed and worked out all the logical consequences of our own living system. It is human arrogance and human arrogance alone that denies this logical possibility.
"To suppose that a life-form based on exactly the same system as ours, the same complex molecular jigsaw bits, had any part in this grander scheme of things would be to beg the question of origins again. The ultimate cosmic intelligence would need to be comprised of different units from those of our own life-form, possibly also units that are intrinsically more robust than ours, with an ability perhaps to withstand much higher temperatures. The essential complexity of our own cells and of the omnipresent cosmic bacteria must be due in part to the necessity to replicate. The bare essentials for intelligence and consciousness might be separable from such fragile structures, and the ultimate cosmic intelligence built from these more robust structures could well be thought to persist for exceedingly long timescales, even for an eternity. A prime requirement is that such an intelligence be capable of computation, analysis and exploration of the Universe at large." (pp 138-9)