Intransitive verbs denoting being in a physical configuration often have transitive counterparts that denote moving something into that state; it is also often the case in English and German, in my limited experience of the latter, that the state-expressing verb is irregular, while the motion-expressing verb is regular (or at least more regular): lay has the past tense "laid" (phonologically if not orthographically regular), while "lie" has the confusing "lay"; "sit" has "sat", whereas "set" has … "set", again, though I hypothesize that it was once something like "setted" (like "setzte") before haplological intervention. And in Latin we have "sedēre" and "sedere", and "iacere" and "iacire" (which apparently derives from the same word as does German "jagen"). Hence "Now I lay me down to sleep". (Though directional adverbs complicate things—one could also say "I lay down to sleep" meaning that that is something one did—so we should really ignore them; "I lay down asleep" is more the thing. This doesn't really matter at present. In fact the fact that "down" doesn't seem to modify the sitting in "I sat down" the way "there" does in "I sat there" makes me wonder if it's really an adverb there at all, something I might have half a chance of thinking intelligently about if I really knew anything about English grammar.)
But what of compounds of these words, even those that do not denote physical configurations or movements? Well, take "possidere": to possess. Profligate Latin also has "possidēre", to come into or take possession of; there appears to be a similar contrast between "besitzen" and "besetzen". But poor English has no analogous term! Fortunately, that there should be one, and what it should mean, are so obvious that the only real issue is orthographical.
The issue is somewhat complicated by the fact that "sit" is the state, "set" the movement, but "possess" is the state again; it strains the relationship. (Also, "possess" is regular, though perhaps with diligence "possass" can be made to catch on.) A bout of confusion led me to think that "posit" was a possibility before remembering that it already exists in English and means something quite different (and comes from a different Latin word, "ponere"; it is interesting, to me, that German sometimes uses "setzen" to match Latin "ponere", as in "voraussetzen"/"praesupponere" ; I have always thought that this is a calque, but I don't really know—there would be a mismatch, in that the "sup" comes from "sub", and that doesn't fit with "aus"). So perhaps we should restore vocalic symmetry, even though the words cannot match directly, and neologize thus: "possiss". As in: "I possiss the house on Tuesday." A fairly useless word, since it will mean nothing that "take possession of" does not currently adequately express, but perhaps it will find a niche. (Tricks with scansion?) In any case, the utility of the word is hardly the point.
 It was only after I realized the connection between the "pose/pos" of "suppose" and "posit", the fourth principle part of "ponere" (= "positus"), and its second that I was able to understand the names of the modi ponens tollensque.