We often take vicarious pride in the greatness of humanity. I say “vicarious” because the greatness that we assume as belonging to our humanity is really the work of a few persons by whom we define that humanity. If we were to define humanity differently – that is, by the deeds of the typical member of the species Homo sapiens – we should think that humanity was a concept signifying little of this greatness. On the other hand, when we take for ourselves a view of humanity that is predicated on the greatness of a few, we are wont to express surprise at the ignobility of the many – and to wonder at the inhumanity of humanity! As Ralph Adams Cram said,
We do not behave like human beings because most of us do not fall within that classification as we have determined it for ourselves, since we do not measure up to standard. And thus:With our invincible—and most honourable but perilous—optimism we gauge humanity by the best it has to show. From the bloody riot of cruelty, greed and lust we cull the bright figures of real men and women. 
If society is not to be brutish, then we require the preservation of individuals—whence humanity as a civilising and noble ideal might be drawn—over the preponderance of the mass. It is from such individuals that the many-headed might learn humanity, without which barbarism is their natural state. As Lin Yutang said,
Mankind as individuals may have reached austere heights, but mankind as social groups are still subject to primitive passions, occasional back-slidings and outcroppings of the savage instincts, and occasional waves of fanaticism and mass hysteria. 
Or, as Nietzsche put it,
Madness in individuals is something rare—but in groups, parties, peoples, and ages, it is the rule. 
A defence of civilised values is quite difficult, however, against the intellectualised advance of mass-barbarism; for the latter also has in its favour a deep visceral appeal: something of the baseness of humanity as a whole, and thus something of which we all have in common.
‘The individual’ . . . this category cannot be taught; the use of it is an art, a moral task, and an art the exercise of which is always dangerous and at times might even require the life of the artist. For that which divinely understood is the highest of all things will be looked upon by a self-opinionated race and the confused crowd as lese majesté against the ‘race’, the ‘masses’, the ‘public’, etc. 
The danger is that in the process of mass-barbarisation, he will be made criminal who fulfils the duties necessary for the preservation of civilisation.
(That said, I feel I need to get out more.)
 R.A. Cram, “Why We Do Not Behave Like Human Beings”, in American Mercury, September 1932, reproduced online at Fulton’s Lair.
 Lin Yutang, “On Having a Mind”, The Importance of Living (London and Toronto: William Heinemann, 1938), p.65.
 F.W. Nietzsche, Jenseits von Gut und Böse (München: Wilhelm Goldmann Verlag, n.d.), §156, p.71. [“Der Irrsinn ist bei einzelnen etwas Seltenes,—aber bei Gruppen, Parteien, Völkern, Zeiten die Regel.”]
 Søren Kierkegaard, The Journals of Søren Kierkegaard, ed. A. Dru, (London: Fontana Books, 1958), p. 134.