question over which Locke and Leibnitz dispute。 The expression “eternal truths” is current even
in these modern times； and it signifies the universal determinations and relations which exist entirely
on their own account。 The word ‘Inborn’ is however a clumsy and stupid expression； because
the conception of physical birth thereby indicated； does not apply to mind。 To Descartes inborn
ideas are not universal； as they are to Plato and his successors； but that which has evidence；
immediate certainty； an immediate multiplicity founded in thought itself — manifold conceptions in
the form of a Being； resembling what Cicero calls natural feelings implanted in the heart。 We would
rather say that such is implied in the nature and essence of our mind and spirit。 Mind is active and
conducts itself in its activity in a determinate manner； but this activity has no other ground than its
freedom。 Yet if this is the case more is required than merely to say so； it must be deduced as a
necessary product of our mind。 We have such ideas； for instance； in the logical laws： “From
nothing comes nothing；” “A thing cannot both be and not be；” （27） as also in moral principles。
These are facts of consciousness which Descartes however soon passes from again； they are only
present in thought as subjective； and he has thus not yet inquired respecting their content。
As regards things； on which Descartes now directs his attention； the other side to these eternal
verities； the universal determinations of things are substance； permanence； order； &c。 （28） He then
gives definitions of these thoughts； just as Aristotle draws up a list of the categories。 But although
Descartes laid it down formerly as essential that no hypotheses must be made； yet now he takes
the conceptions； and passes on to them as something found within our consciousness。 He defines
substance thus： “By substance I understand none other than a thing （rem） which requires no other
something for existence； and there is only one thing； namely God； which can be regarded as such a
substance requiring no other thing。” This is what Spinoza says； we may say that it is likewise the
true definition； the unity of Notion and reality： “All other” （things） “can only exist by means of a
concurrence （concursus） of God；” what we still call substance outside of God thus does not exist
for itself； does not have its existence in the Notion itself。 That is then called the system of
assistance （systema assistenti？） which is； however； transcendental。 God is the absolute uniter of
Notion and actuality； other things； finite things which have a limit and； stand in dependence； require
something else。 “Hence if we likewise call other things substances； this expression is not applicable
both to them and to God univoce； as is said in the schools； that is to say no definite significance
can be given to this word which would equally apply both to God and to the creatures。” （29）
“But I do not recognize more than two sorts of things； the one is that of thinking things； and the
other that of things which relate to what is extended。” Thought； the Notion； the spiritual； the
self…conscious； is what is at home with itself； and its opposite is contained in what is extended；
spatial； separated； not at home with itself nor free。 This is the real distinction （distinctio realis） of
substances： “The one substance can be clearly and definitely comprehended without the other。 But
the corporeal and the thinking and creating substance can be comprehended under this common
notion； for the reason that they are things which require God’s support alone in order to exist。”
They are universal； other finite things require other things as conditions essential to their existence。
But extended substance； the kingdom of nature； and spiritual substance； do not require one
another。 They may be called substances； because each of them constitutes an entire range or
sphere； an independent totality。 But because； Spinoza concluded； each side； the kingdom of
thought as well as nature； is one complete system within itself； they are likewise in themselves； that
is absolutely； identical as God； the absolute substance； for thinking spirit this implicit is thus God；
or their differences are ideal。
Descartes proceeds from the Notion of God to what is created； to thought and extension； and
from this to the particular。 “Now substances have several attributes without which they cannot be
thought〃 — that signifies their determinateness — 〃but each has something peculiar to itself which
constitutes its nature and essence〃 — a simple universal determinateness — 〃and to which the
others all relate。 Thus thought； constitutes the absolute attribute of mind；” thought is its quality；
“extension is〃 the essential determination of corporeality； and this alone is “the true nature of
body。 What remains are merely secondary qualities； modes； like figure and movement in what is
extended； imagination； feeling and will in thinking； they may be taken away or thought away。 God
is the uncreated； thinking substance。” （30）
Descartes here passes to what is individual； and because he follows up extension he arrives at
matter； rest； movement。 One of Descartes’ main points is that matter； extension； corporeality； are
quite the same thing for thought； according to him the nature of body is fulfilled in its extension； and
this should be accepted as the only essential fact respecting the corporeal world。 We say that
body offers resistance； has smell； taste； colour； transparency； hardness； &c。； since without these
we can have no body。 All these further determinations respecting what is extended； such as size；
rest； movement； and inertia； are； however； merely sensuous； and this Descartes showed； as it had
long before this been shown by the Sceptics。 Undoubtedly that is the abstract Notion or pure
essence； but to body or to pure existence； there likewise of necessity pertains negativity or
diversity。 By means of the following illustration Descartes showed that with the exception of
extension； all corporeal determinations may be annihilated； and that none can be absolutely
predicated。 We draw conclusions respecting the solidity and hardness of matter from the
resistance which a body offers to our disturbance； and by means of which it seeks to hold its
place。 Now if we admit that matter as we touch it always gives way to as like space； we should
have no reason for ascribing to it solidity。 Smell； colour； taste； are in the same way sensuous
qualities merely； but what we clearly perceive is alone true。 If a body is ground into small parts； it
gives way； and yet it does not lose its nature； resistance is thus not essential。（31） This
not…being…for…itself is however a quantitatively slighter resistance only； the resistance always
remains。 But Descartes desires only to think； now he does not think resistance； colour； &c。； but
apprehends them by the senses only。 Hence he says that all this must be led back to extension as
being special modifications of the same。 It is undoubtedly to the credit of Descartes that he only
accepts as true what is thought； but the abrogation of these sensuous qualities simply represents
the negative movement of thought： the essence of body is conditioned through this thought； that is；
it is not true essence。
Descartes now makes his way from the Notion of extension to the laws of motion； as the universal
knowledge of the corporeal in its implicitude； he shows that there is no vacuum； for that would be
an extension without bodily substance； i。e。 a body without body； that there are no atoms （no
indivisible independent existence）； for the same reason； viz。； because the essence of body is
extension。 He further shows that a body is set in motion by something outside of it； but of itself it
continues in a condition of rest； and likewise it must； when in a condition of movement； be brought
to rest by another outside of it — this is the property of inertia。（32） These are unmeaning
propositions； for an abstraction is involved for instance in asserting simple rest and movement in
their opposition。
Extension and motion are the fundamental conceptions in mechanical physics； they represent the
truth of the corporeal world。 It is thus that ideality comes before the mind of Descartes； and he is
far elevated above the reality of the sensuous qualities； although he does not reach so far as to the
separation of this ideality。 He thus remains at the point of view of mechanism pure and simple。
Give me matter （extension） and motion and I will build worlds for you； is what Descartes virtually
says。（33） Space and time were hence to him the only determinations of the material universe。 In
this； then； lies the mechanical fashion of viewing nature； or the natural philosophy of Descartes is
seen to be purely mechanical。（34） Hence changes in matter are due merely to motion； so that
Descartes traces every relationship to the rest and movement of particles； and all material diversity
such as colour； and taste — in short； all bodily qualities and animal phenomena — to mechanism。 In
living beings processes such as that of digestion are mechanical effects which have as principles；
rest and movement。 We here see the ground and origin of the mechanical philosophy； but further
on we find that this is unsatisfactory； for matter and motion do not suffice to explain life。 Yet the
great matter in all this is that thought goes forward in its determinations； and that it constitutes from
these thought…determinations the truth of nature。
In his consideration of the system of the world and the movement of the heavenly bodies；
Descartes has worked out the mechanical view more fully。 He thus comes to speak of the earth；
the sun； &c。； and of his conception of the circling motion of the heavenly bodies in the form of
vortices： of metaphysical hypotheses as to how small particles pass into； out of； and through pores
and act on one another； and finally to saltpetre and gunpowder。（35）
Universal reflections should have the first claim on our attention； but on the other hand the
transition to the determinate is accomplished in a system of Physics which is the result of
observations and experienc