  A minimal practical formal structure for a fundamental theory is suggested. A
mechanism that produces such a structure is reviewed. The proposed mechanism
has possibilities of producing non-canonical phenomena in SU(2) and SU(3)
quantum gauge theories. These might provide testable conditional predictions.
One possibility is a vacuum condensate of SU(2) gauge fields associated to
certain trajectories of the SU(2) Yang-Mills flow.
  Contents
  1 Formal fundamental physics
  1.1 Against Quantum Gravity
  1.2 Against mathematical idealizations
  2 A minimal practical formal structure
  2.1 An effective QFT for distances > L and an effective S-matrix for
distances < L, for observers at every scale L >> l_P
  2.2 QFT renormalization group operates from smaller distance L to larger;
S-matrix renormalization group operates from larger L to smaller
  2.3 An S-matrix does not imply a hamiltonian
  3 A mechanism that produces such a formal structure
  3.1 Summary
  3.2 2d-QFT of the string worldsheet
  3.3 Effective string S-matrix with IR cutoff L
  3.4 Effective 2d coupling constants
  3.5 Implement the S-matrix renormalization group
  3.6 Production of an effective QFT with UV cutoff L
  3.7 Possible non-canonical degrees of freedom and couplings in SU(2) and
SU(3) quantum gauge theory
  3.8 2d winding modes and 2d instantons
  3.9 Vacuum condensate of SU(2) Yang-Mills flow defects
  4 To do
  Appendix. Notes on the line of thought
  A.1 Search for a mechanism that produces QFT
  A.2 Pragmatism and the S-matrix philosophy
