"Cum formarum naturalium et corporalium esse non consistat iiisi in 

 unione ad materiam, ejusdem agentis esse videtur eas producere cujus est 

 materiam transmutare. Secundo, quia cum hujusmodi formae non excedant 

 virtutem et ordinem et facultatem principiorum agentium in natura, nulla 

 videtur necessitas eorum originem in principia reducere altiora." x'^quinas, 

 De Pat. Q. ui, a, 11. (Quoted in Brit. Assoc. Address, Section D, 1911.) 



"...I would that all other natural phenomena might similarly be deduced 

 from mechanical principles. For many things move me to suspect that 

 everythmg depends upon certain forces, in wtue of which the particles of 

 bodies, through forces not yet understood, are either impelled together so as 

 to cohere in regular figures, or are repelled and recede from one another." 

 Newton, in Preface to the Principia. (Quoted by ]VIr W. Spottiswoode, 

 Brit. Assoc. Presidential Address, 1878.) 



"When Science shall have subjected all natmal phenomena to the laws of 

 Theoretical Mechanics, when she shall be able to predict the result of every 

 combination as unerringly as Hamilton predicted conical refraction, or Adams 

 revealed to us the existence of Neptune, — that we cannot say. That day 

 may never come, and it is certainly far in the dim futiu-e. We may not 

 anticipate it, we may not even call it possible. But none the less are we 

 bound to look to that day, and to labour for it as the crowning triumph of 

 Science : — when Theoretical Mechanics shall be recognised as the key to every 

 physical enigma, the chart for every traveller through the dark Infinite of 

 Nature." J. H. Jellett, in Brit. Assoc. Address, Section A, 1874. 



