=4. Modality.=--Neither Wolff nor Reimarus gives any account of modality.[706] Baumgarten classifies judgments as pure or modal (existing in _four_ forms, necessity, contingency, possibility, impossibility). Baumeister and Thomasius also recognise four forms of modality. Meier distinguishes between pure judgment (_judicium purum_) and impure judgment (_judicium modale_, _modificatum_, _complexum qua copula_), but does not classify the forms of modality. Lambert alone[707] classifies judgments as “possible, actual (_wirklich_), necessary, and their opposite.” But when Kant adopts this threefold division, the inclusion of actuality renders the general title “modality” inapplicable in its traditional sense. The expression of actuality in the assertoric judgment involves no adverbial modification of the predicate. Also, in its “affirmative” and “categorical” forms it has already been made to yield two other categories. Kant speaks of the problematic, the assertoric, and the apodictic forms of judgment as representing the stages through which knowledge passes in the process of its development. “These three functions of modality are so many momenta of thought in general.” This statement has been eulogised by Caird,[708] as being an anticipation of the Hegelian dialectic. As a matter of fact, Kant’s remark is irrelevant and misleading. The advance from consciousness of the problematic, through determination of it as actual to its explanation as necessary, represents only a psychological order in the mind of the individual. Logically, knowledge of the possible rests on and implies prior knowledge of the actual and of the necessities that constitute the actual.[709]