46 THE PHYSICAL BASIS OF LIFE 



Once more, in the plain speech of everyday life, their 

 meaning is : We do not knotv. 



I do not in the least mean by this that our faith in 

 mechanistic methods and conceptions is shaken. It is by 

 following precisely these methods and conceptions that 

 observation and experiment are every day enlarging our 

 knowledge of colloidal systems, lifeless and living. Who 

 will set a limit to their future progress I But I am not 

 speaking of tomorrow but of today; and the mechanist 

 should not deceive himself in regard to the magnitude of 

 the task that still lies before him. Perhaps, indeed, a day 

 may come (and here I use the words of Professor Tro- 

 land)"' when we mav be able "to show how in accordance 

 with recognized principles of physics a complex of spe- 

 cific, autocatalytic, colloidal particles in the germ-cell can 

 engineer the construction of a vertebrate organism"; but 

 assuredly that day is not yet within sight of our most 

 powerful telescopes. Shall we then join hands with the 

 neo-vitalists in referring the unifying and regulatory 

 principle to the operation of an unknown power, a direc- 

 tive force, an archaeus, an entelechy, or a soul ? Yes, if we 

 are ready to abandon the problem and have done with it 

 once for all. No, a thousand times, if we hope really to ad- 

 vance our understanding of the living organism. To say 

 ignoramus does not mean that we must also say ignorahi- 

 nms. I do not l^elieve that a confession of ignorance leaves 

 us with no resource save vitalism. To maintain that o])ser- 

 vation and experiment will not bring us nearer to a solu- 

 tion of the puzzle would be to lapse into the dark ages. 

 Perhaps Professor Henderson is right when he expresses 

 his belief that organization has finally become a category 

 that stands beside those of matter and energy.^** Perhaps 

 there is no problem, or none that we can formulate with- 

 out talking nonsense. Perhaps we should go no further 



