The debate was concluded in a "Point–Counterpoint" feature that was the 1 December 2003 cover story of "Chemical & Engineering News", the newsmagazine of the American Chemical Society. The feature first reproduced Drexler's April 2003 open letter to Smalley. Smalley's response began by apologizing for any offense his September 2001 article had caused, and stating that Drexler's book "Engines of Creation" had triggered Smalley's own interest in nanotechnology. He agreed that "Smalley fingers" could not work, and then asserted that the same reasons that would preclude atomic control of reactions would also preclude the manipulation of larger building blocks, since each molecule would have multiple atoms which would need to be controlled  He then agreed that something like an enzyme or ribosome would be capable of precise chemistry, but asked how the nanorobot would be able to obtain, control, and repair such an enzyme, and noted the incompatibility of many reactions with water-based biological systems, stating that "biology is wonderous in the vast diversity of what it can build, but it can't make a crystal of silicon, or steel, or copper, or aluminum, or titanium, or virtually any of the key materials on which modern technology is built." Smalley asked what kind of "nonaqueous enzymelike chemistry" Drexler would envision for his molecular assemblers to operate upon, calling this "a vast area of chemistry that has eluded us for centuries." Drexler's counterresponse began by returning to Feynman's 1959 talk, stating that "although inspired by biology... Feynman's vision of nanotechnology is fundamentally mechanical, not biological." He characterized the challenges as being that of systems engineering rather than solely chemistry, and referred Smalley to "Nanosystems", with its vision of mechanical control of chemical reactions with no enzymes and no reliance on solvents or thermal motion. He stated:  Drexler reiterated that these molecular assemblers would require no impossible fingers, and would augment solution-phase chemistry to produce macroscopic products with precise arrangements of chemical building blocks, using solution-phase molecular assemblers to bootstrap the construction of more sophisticated assemblers. He concluded by writing:  Smalley began his concluding letter:  Smalley stated his belief that most reactions using mechanosynthesis would simply give the wrong product, and that very few reactions and target molecules would likely be compatible with such an approach. He asserted that any robotic assembler arm would need an enzyme-like tool at its end such would require a liquid medium, and as all known enzymes use water as that medium, the range of products must be limited to the "meat and bone of biology."