The word "practical" having been pronounced, it behoves us to eliminate a misapprehension which leads to the natural sciences (or simply _sciences,_ as they are also called) being said to be practical, in the same sense as those whose aim is action. Bacon was a fervent apostle of the naturalistic movement of modern times and full of this latter idea or preconception. He proclaimed to satiety that _meta scientiarum non aha est quam ut dotetur vita humana novis inventis et copiis_; that they propose to themselves _potentiae et amplitudinis humanae fines in latim proferre_; and that, by means of them, reality _ad usus vitae humanae subigitur_[1] But in our day also, many theorists do not tire of repeating that the sciences are _ordonnées à faction._ Now, this does not suffice to describe the natural sciences, because all knowledge is directed to action, art, philosophy, and history alike, which last, by providing knowledge of the actual situation, is the true and complete precedent and fact, preparatory to action.[2] The misapprehension in favour of the natural sciences arises from the vulgar idea that the only practical things in life are eating, drinking, clothes, and shelter. It is forgotten that man does not live by bread alone, and that bread itself is a spiritual food if it increase the force of spiritual life. But further: the natural sciences, just because they are composed of empirical concepts (which are not true knowledge), do not _directly_ subserve action, since in order to act it is necessary to return from them to the precise knowledge of the individual actual situation. That is to say, in ordinary parlance, _abstractions_ must be set aside and it must be seen _how things_ truly and properly _stand._ The patient, the individual patient, is treated, not the malady; Socrates or Callias (as Aristotle said), not man in general: θεραπευτὸν τὸ καθ' ἕκαστον: knowledge of _materia medica_ does not suffice; the _clinical eye_ is needed. The natural sciences are not directed to action, but _are,_ themselves, actions: their practical character is not extrinsic, but _constitutive._ They are actions, and are therefore not directed to action, but to aid the cognitive spirit. Thus they subserve action (that is, other actions) only in an indirect way. If an action does not become knowledge, it cannot give rise: to a new action. [Sidenote: _Impossibility of unifying them in a concept._]