In the middle ages 197

ophy denies the existence in our minds of these two

concepts — but also the substance and the accidents

exist independently and outside of our minds. In

the order of existence, as in the order of our

thought, substance and accident are relative to each

other. One who succeeds in proving the external

existence of the accident^ (for instance, the thick-

ness of the tree) , also proves the existence of the

substance (that 'is, the tree). If the act of walking

is not an illusion but something real, the same must

be equally trufe. of the substantial being who walks,

without whom there would be no act of walk-

ing. The substance, or subject, exists in and by it-

self; it is self-sufficient. But it is also the support

of all the rest, which therefore are called accidentia

(id quod accidit alicui rei) .

As for my own substance, the substance of my-

self as a human being, — that is personality — there

is the witness of consciousness, by its several ac-

tivities, to the existence of just such a substantial

Ego. In thinking and speaking, and so on, I at-

tain to my own existing substance. The scholastics

were essentially familiar with the cogito ergo sum.

Without permanence of personality, memory would

be inexplicable. If I were only a collection of

1 Scholasticism proves the objectivity of our external sense-per-

ception by the mark of passivity (of which we are conscious) and

by the principle of causality: quidquid movetur ah alio movetur.

We are conscious of being passive in external sensation; conse-

quently we do not create it, — therefore it must come from a non-ego.

198 PHILOSOPHY AND CIVILIZATION

ephemeral activities, what Taine calls a collection

of shy-rochets of consciousness {"gerhes lumineu-

ses"), how could one sky-rocket remember an-

other? How could I then remember in maturity

the acts of my boyhood? But, not only do I re-

member such acts, I am also conscious of being the

same 'personality ; my acts disappear, my body

changes, but I remain a subject independent of

these acts and changes.

The frequent misunderstanding of the scholastic

theory of substance rests upon two misconcep-

tions of what that theory involved: first, that one

knows wherein one substance differs from another;

second, that substance is something underlying ac-

cidental realities. Now, as regards the former,

scholastic philosophy never pretended to know

wherein one substance differed from another in the

external world. It thought of substance as an idea

resulting from reasoning, which does not instruct

regarding what is specific in each of the substances f

one knows that they are and must be, but never

tiohat they are. Indeed, the idea of substance is es-

sentially thin. And the same may be said of the

Ego, as the substance best known to each individual

person ; consciousness witnesses to its existence, but

never to its nature, — as Descartes erroneously sup-

posed. A proof that consciousness alone does not

instruct us regarding our own nature, says scholas-

ticism, is tlie discussion among philosophers on

- See above, p. 184.