 As Rickert’s title emphasizes, he conceived of history as a logical notion, as a certain way of forming concepts. The traditional logic, he claims, considers only concepts formed by abstracting away from individual particularities to form general representations. But this method has its limit: it cannot explain how we form concepts of individuals. History is a logical procedure for forming concepts of individuals, as, for instance, a historical work on Caesar would produce a concept of Caesar. In calling the products of historical research “concepts”, Rickert is combating the view that a historian merely collects facts and reports them. Rather, the historian sifts through the potentially infinite number of facts about her subject and isolates, using some principle of selection, the facts about her subject that are essential for  history.[29]  Though Rickert employs the traditional logical notion of an individual to characterize the subject of historical concepts, he uses the term in a distinctive way. Individuals are unique and they are indivisible or irreplaceable. An adequate historical concept of Julius Caesar needs to include those features that make him unique, and unlike any other individual. Rickert uses the example of the Koh-i-noor diamond to illustrate the indivisibility or irreplaceability of an historical individual. Of course there are distinctive facts about this diamond that distinguish it from all other hunks of carbon; but the same could be said of any lump of coal. However, from the point of view of history, it is indifferent whether one lump of coal that was used to power a locomotive carrying Queen Victoria would have been destroyed and replaced by some other lump of coal. But, from the point of view of history, the massive diamond that the Queen herself was wearing is hardly replaceable. Furthermore, Rickert insisted that historical concepts, although they are of an individual, are nonetheless general in the sense that the principles of selection employed in forming these concepts are universally valid for all  historians.[30]