I’ve sometimes pondered upon the etymology of such terms. They strike me as somewhat creepy. As if there’s a preternatural audience watching. Maybe I think too much.

None-the-less, here are the obvious explanations:

Human Race

The Bible stipulated that mankind was derived from one common pair of ancestors. The concept of the ‘chosen people’ was integrated into Scriptural cosmogony; it resided in the idea that adherence to Moses' commandments qualified people for participation in the Abrahamitic covenant between God and the Jewish people. As for the cultural foundations of the Christian creed, the notion of the soul as the essential part of all humans prevented fixation on physiology alone as inherent in the concept of race. According to common Christian understanding, all converts to the faith, whatever their complexion might be, underwent what was evidently thought of as a spiritual ‘white-washing’. Christian iconography abounds with depictions of this procedure in which the coloured convert was washed white. It was an allusion to Jeremiah 13: 23 (‘Can the Ethiopian change his skin, or the leopard his spots? Then may ye also do good, that are accustomed to do evil’). Christian doctrine confirmed that the curse of Ham could be removed. In another respect, too, Christian theory contradicted the Scriptural narrative. From the Jewish historian Flavius Josephus (ad 37-c.97) onwards, writers divided mankind into the posterity of Shem, Ham, and Japhet. The Japhetites were considered to inhabit Europe; the Shemites resided in the region of the Pacific Ocean and the Near East; the Hamites were to be found in Africa. The Catholic Church denounced this division, which threatened its claim to universality. Christian theory asserted that all mankind was one — though, of course, the ideal was remote from actual practice.

Until the eighteenth century, Judaeo-Christian traditions and classical theory dominated all philosophizing on mankind. Human nature was discussed in terms of ideas about polis and ecclesia. The identity of a people was considered to depend on its faith, and on the fact that all citizens were subject to the same law. Philosophers had no concept of ‘racial’ traits, instead they discussed what they called ‘national character’. Its shape was seen to depend on climate and geographical station — humoralism, the complex concept of an interplay between the outside world and human temperaments, lasted well into the nineteenth century. Until the middle of the eighteenth century it influenced all attempts to account for human diversity. On the whole, references in early modern literature to, say, the African or the Chinese ‘race’ do not imply the existence of a set of physical categories adding up to a system of human classification. And the notion of ‘purity of blood’ had no biological connotations.

During the sixteenth century the term ‘race’ had a socio-political rather than an anthropological meaning. It was part of the historiographical appreciation of the Frankish dynasties. The French historian François Hotman (1524-90) denied that the political institutions of Greece and Rome were the models of German and Frankish government. Distinguishing between the autocratic monarchies of antiquity and Franco-Germanic freedom, he supported the notion that different peoples were endowed with different spirits. As Europeans discovered foreign parts, the understanding of ‘race’ was increasingly extended to denote not only noble families, but entire peoples. However, the concept was still shaped by political concepts as opposed to biology.

As an ethnological category, ‘race’ is a modern idea. From the Renaissance onwards, study of the natural realm was increasingly distinguished from metaphysics. Francis Bacon, Thomas Hobbes, John Locke, Jean Bodin, and others relieved Aristotle's philosophy of its emphasis on the essences. The pursuit of evidence became the paramount scientific occupation; empirical observation of difference supplanted unifying philosophies. Classical learning gradually lost its grip on the European mind. As a result, ‘racial’ differences became independent of political discourse, and instead were investigated as natural phenomena.

Theatre of War

The term seems to have been coined by Carl von Clausewitz in his book "On War". Specifically in his book Clausewitz defines the term as one that:

"Denotes properly such a portion of the space over which war prevails as has its boundaries protected, and thus possesses a kind of independence. This protection may consist in fortresses, or important natural obstacles presented by the country, or even in its being separated by a considerable distance from the rest of the space embraced in the war. Such a portion is not a mere piece of the whole, but a small whole complete in itself; and consequently it is more or less in such a condition that changes which take place at other points in the seat of war have only an indirect and no direct influence upon it.

To give an adequate idea of this, we may suppose that on this portion an advance is made, whilst in another quarter a retreat is taking place, or that upon the one an army is acting defensively, whilst an offensive is being carried on upon the other. Such a clearly defined idea as this is not capable of universal application; it is here used merely to indicate the line of distinction."