A lot of people seem to think that reductionism is a philosophy. But it most definitely is not. That reductionism is correct is a hypothesis about the properties of nature and it is a hypothesis that has so far been supported by every single experiment that has ever been done. I cannot think of *any scientific fact that is better established than that the properties of the constituents of a system determine how the system works. ...I agree with this, but see this recent paper:
Indeed, the whole history of science until now has been a success story of reductionism. Biology can be reduced to chemistry, chemistry can be reduced to atomic physics, and atoms are made of elementary particles. This is why we have computers today.
The relationship between the chemical picture of an isolated molecule and ttuff.hat arising from the eiegenfunctions of the Schrodinger Coulomb Hamiltonian [for] the isolated molecule are examined and discussed.Apparently the program to reduce chemistry to atomic physics has run into some problems. We still need chemistry, because the atomic physicists cannot explain some basic stuff.