Humanitarianism and strength

Reading 'All things considered', I come upon interesting essays on a multitude of topics. This particular essay shows a interesting line of argument.
First of all, the familiar topic of 'progress' is dealt with: 'Human history is so rich and complicated that you can make out a case for any course of improvement or retrogression. I could make out that the world has been growing more democratic, for the English franchise has certainly grown more democratic. I could also make out that the world has been growing more aristocratic, for the English Public Schools have certainly grown more aristocratic.'
After this introduction, Chesterton discusses the relations between European civilization and 'savages': one of the reasons that the 'ruder or more sluggish races' may respect the civilization of Christendom is 'because it does not use their own coarse and cruel expedients'. This is a reason never to fight these civilizations with their own weapons.
The argument continues that 'the elements that make Europe upon the whole the most humanitarian civilization are precisely the elements that make it upon the whole the strongest.' Imagination has caused the invention of both the machine-gun and the ambulance.
Lastly, Chesterton warns us that the barbaric notions about 'forces outside man', like heredity, or determinism, are gaining strength in his time. He argues that the characteristic of the 'true civilized man' is that he is a 'free man, and is always talking about what he may do'. Another silly modern notion is discussing 'material substances' instead of 'ideas', e.g. 'the problem of drink' versus 'gluttony or excess'. These cases of determinism and 'uncivilized materialism' may be a sign of the 'modern danger' of a 'slow return towards barbarism'.