Note 66 — Chapter III · * OTHER COMPANIONS OF SOKRATES.

The same doctrine as that of the Megaric Diodorus is declared by Hobbes in clear and explicit language (First Grounds of Philosophy, ii. 10, 4-5):—“That is an impossible act, for the production of which there is no power plenary. For seeing plenary power is that in which all things concur which are requisite for the production of an act, if the power shall never be plenary, there will always be wanting some of those things, without which the act cannot be produced. Wherefore that act shall never be produced: that is, that act is impossible. And every act, which is not impossible, is possible. Every act therefore which is possible, shall at some time or other be produced. For if it shall never be produced, then those things shall never concur which are requisite for the production of it; wherefore the act is impossible, by the definition; which is contrary to what was supposed.

“A necessary act is that, the production of which it is impossible to hinder: and therefore every act that shall be produced, shall necessarily be produced; for that it shall not be produced is impossible, because, as has already been demonstrated, every possible act shall at some time be produced. Nay, this proposition — What shall be shall be — is as necessary a proposition as this — A man is a man.

“But here, perhaps, some man will ask whether those future things which are commonly called contingents, are necessary. I say, then, that generally all contingents have their necessary causes, but are called contingents, in respect of other events on which they do not depend — as the rain which shall be to-morrow shall be necessary, that is, from necessary causes; but we think and say, it happens by chance, because we do not yet perceive the causes thereof, though they exist now. For men commonly call that casual or contingent, whereof they do not perceive the necessary cause: and in the same manner they use to speak of things past, when not knowing whether a thing be done or not, they say, It is possible it never was done.

“Wherefore all propositions concerning future things, contingent or not contingent, as this — It will rain to-morrow, or To-morrow the sun will rise — are either necessarily true or necessarily false: but we call them contingent, because we do not yet know whether they be true or false; whereas their verity depends not upon our knowledge, but upon the foregoing of their causes. But there are some, who, though they will confess this whole proposition — To-morrow it will either rain or not rain — to be true, yet they will not acknowledge the parts of it, as, To-morrow it will rain, or To-morrow it will not rain, to be either of them true by itself; because (they say) neither this nor that is true determinately. But what is this true determinately, but true upon our knowledge or evidently true? And therefore they say no more but that it is not yet known whether it be true or not; but they say it more obscurely, and darken the evidence of the truth with the same words by which they endeavour to hide their own ignorance.”