We ought here to note the sense in which Plato uses the word Necessity. This word is now usually understood as denoting what is fixed, permanent, unalterable, knowable beforehand. In the Platonic Timæus it means the very reverse:--the indeterminate, the inconstant, the anomalous, that which can neither be understood nor predicted. It is Force, Movement, or Change, with the negative attribute of not being regular, or intelligible, or determined by any knowable antecedent or condition--_Vis consili expers_. It coincides, in fact, with that which is meant by _Freewill_, in the modern metaphysical argument between Freewill and Necessity: it is the undetermined or self-determining, as contrasted with that which depends upon some given determining conditions, known or knowable. The Platonic Necessity[20] is identical with the primeval Chaos, recognised in the Theogony or Kosmogony of Hesiod. That poet tells us that Chaos was the primordial Something: and that afterwards came Gæa, Eros, Uranus, Nyx, Erebus, &c., who intermarried, males with females, and thus gave birth to numerous divine persons or kosmical agents--each with more or less of definite character and attributes. By these supervening agencies, the primeval Chaos was modified and regulated, to a greater or less extent. The Platonic Timæus starts in the same manner as Hesiod, from an original Chaos. But then he assumes also, as coæval with it, but apart from it, his eternal Forms or Ideas: while, in order to obtain his kosmical agents, he does not have recourse, like Hesiod, to the analogy of intermarriages and births, but employs another analogy equally human and equally borrowed from experience--that of a Demiurgus or constructive professional artist, architect, or carpenter; who works upon the model of these Forms, and introduces regular constructions into the Chaos. The antithesis present to the mind of Plato is that between disorder or absence of order, announced as Necessity,--and order or regularity, represented by the Ideas.[21] As the mediator between these two primeval opposites, Plato assumes Nous, or Reason, or artistic skill personified in his Demiurgus: whom he calls essentially good--meaning thereby that he is the regularising agent by whom order, method, and symmetry, are copied from the Ideas and partially realised among the intractable data of Necessity. Good is something which Plato in other works often talks about, but never determines: his language implies sometimes that he knows what it is, sometimes that he does not know. But so far as we can understand him, it means order, regularity, symmetry, proportion--by consequence, what is ascertainable and predictable.[22] I will not say that Plato means this always and exclusively, by Good: but he seems to mean so in the Timæus. Evil is the reverse. Good or regularity is associated in his mind exclusively with rational agency. It can be produced, he assumes, only by a reason,