thetical proposition is false, if the contradictory of its conclusion does not conflict with the premiss, e.g. " If it is day, Dion is walking." For the statement " Dion is not walking " does not conflict with the premiss " It is day." An inferential proposition is true if starting from a true premiss it also has a consequent conclusion, as e.g. " Since it is day, the sun is above the horizon." But it is false if it starts from a false premiss or has an inconsequent conclusion, as e.g. " Since it is night, Dion is walking," if this be said in day-time. A causal proposition is true if its conclusion really follows from a premiss itself true, though the premiss does not follow conversely from the conclusion, as e.g. " Because it is day, it is light," where from the " it is day " the "it is light " duly follows, though from the statement " it is light " it would not follow that " it is day." But a causal proposition is false if it either starts from a false premiss or has an inconsequent conclusion or has a premiss that does not correspond with the conclusion, as e.g. " Because it is night, Dion is walking." A probable judgement is one which induces to assent, e.g. " Whoever gave birth to anything, is that thing's mother." This, however, is not necessarily true ; for the hen is not mother of an egg. Again, some things are possible, others impossible ; and some things are necessary, others are not necessary. A proposition is possible which admits of being true, there being nothing in external circumstances to prevent it being true, e.g. " Diocles is alive." Impossible is one which does not admit of being true, as e.g. " The earth flies." That is necessary which besides being true does not admit of being