Sorry about the naff link and thanks for the correction, LH.
As Dave says this sort of approach can clarify thinking. Descartes’ “I think, therefore I am” presupposes what it sets out to prove - “Thinking occurs therefore a thinker must exist” is better in E- Prime. Who cares? Darwin’s Bulldog TH Huxley (another biologist like Dawkins!) was on the right track:
“...it is proper for me to point out that we have left Descartes himself some way behind us. He stopped at the famous formula, “I think, therefore I am.” Yet a little  consideration will show this formula to be full of snares and verbal entanglements. In the first place, the “therefore” has no business there. The “I am” is assumed in the “I think,” which is simply another way of saying “I am thinking.” And, in the second place, “I think” is not one simple proposition, but three distinct assertions rolled into one. The first of these is, “something called I exists;” the second is, “something called thought exists;” and the third is, “the thought is the result of the action of the I."”