as above

1. The Origins of Knowledge
Knowledge Innatism

2. The opposing view: Rationalism - key doctrines
1. Innatism
– some truths are innate
– some concepts or knowledge are
inherent
2. The Intuition and Deduction Thesis
– other necessary/a priori truths
can be uncovered by the rational
intellect
– Rational intuition and rational
deduction are how the intellect
does this

3. Knowledge Innatism
• The doctrine that we have access to at least some innate or intuited or
deduced a priori propositional knowledge.
– Innate = inherent in us, not derived from experience.
– Intuited/deduced – seen to be true using rational insight alone, or
worked out from this insight
– a priori = true quite independently of experience
• Knowledge innatism is invoked to explain how we can have knowledge
(of certain, unusual propositions) that seems to go beyond
experience, either
– because its subject matter transcends experiential reality
– or because of its universal applicability

4. Candidates for innate knowledge
• Common candidates for innate knowledge:
– The laws of nature
– logical and mathematical truths
– ethical truths
– metaphysical truths concerning transcendent objects like
God, the soul, and Plato’s Forms.
• Examples of such knowledge-claims:
– ‘I know that all events have a cause’
– ‘I know that God exists’
– ‘I know that lying is wrong’
Task: add to your list of exemplar knowledge-claims

5. What is Rational Intuition?
• Seeing something to be
true ‘in a flash’
• Perhaps seeing it to be true
independently of
experience
• ‘Indubitable rightness’ or
intellectual certainty
• Descartes’ ‘C + D = T’
notion

6. What is Rational Demonstration?
• Seeing something to be true
because
– it follows as a consequence
from other self-evident
truths…
– …which are more basic and
more self-evident
– ‘Inferential chains’ are
formed…
– …as you deduce one certain
truth from another…
Step 1
•God exists
Step 2
•And God isn’t a deceiver
Step 3
•So I can trust my senses
(when they are checked by
my intellect)
Step 4
•They tell me the external
world exists.
Step 5
•And so the external world
does exist!
Descartes: Meditation 6

7. Arguments for knowledge innatism 1 –
Plato’s Doctrine of the Forms
• Plato’s arguments are underpinned by Plato’s metaphysics – his picture of the
essential nature of the universe that underlies the physical world.
• Plato’s metaphysics (a.k.a. ‘Platonic Realism’), remember = there are two worlds:
• The world of the senses or world of becoming. This world lacks reality in that
it is full of illusions and beliefs only, and does not contain the proper objects
of knowledge. It is populated by mutable and transient objects.
• The world of the intellect or world of being. This world is the zone of thought
and knowledge. It is populated by the Forms or Universals, changeless and
eternal hyperreal objects.
• The world of the Forms causes the world of physical objects to come into
being.
• Plato thus values the world of the mind rather more than the world of the
senses.
• The Allegories of the Cave, the Sun, the Divided Line are all meant to illustrate the
Doctrine of the Forms.

8. Plato’s Simile of the Cave
• This entire allegory, I said, you may now apprehend, dear
Glaucon: the prison-house is the world of sight, the light of the
fire is the sun, and the journey upward is the ascent of the soul
into the intellectual world. And in the world of knowledge the
idea of good appears last of all, and is seen only with an effort,
and is the universal author of all things beautiful and right, the
source of reason and truth, the power upon which he who would
act rationally either in public or private life must have his eye
fixed.
• Our argument shows that the power and capacity of learning
exists in the soul already…the instrument of knowledge can only
by the movement of the whole soul be turned from the world of
becoming into that of being, and learn by degrees to endure the
sight of being, and of the brightest and best of being, or, in other
words, of the good.

9. Plato’s Simile of the Sun
“This reality, then, that gives truth to the
objects of knowledge and the power of knowing
to the knower, is the idea of good, and you must
conceive it as being the cause of knowledge,
and of truth in so far as known. Examine the
similitude of it still further in this way…the sun
not only furnishes to visibles the power of
visibility but it also provides for their generation
and growth…In like manner, then, the objects of
knowledge not only receive from the presence
of the good their being known, but their very
existence and essence is derived to them from
it.’

10. Innate knowledge: The Slave Boy Example
• Athenian society was
slave-owning.
• Most households had at
least one slave.
• Many had three or four.
• Why does Socrates
choose a slave-boy for an
epistemological
experiment?

11. Innate knowledge: Platonic Dualism
Q - What does the Slave Boy’s quick grasp of the geometry of
squares and triangles show?
A: (SOCRATES) Either then he has at some time acquired the
knowledge which he now has, or he has always possessed it. If
he always possessed it, he must always have known…if he did
not acquire them in this life, isn't it immediately clear that he
possessed and had learned them during some other period… his
soul has been for ever in a state of knowledge? …if the truth
about reality is always in our soul, the soul must be immortal,
and one must take courage and try to discover – that is, to
recollect what one doesn't happen to know, or (more correctly)
remember, at the moment.

12. The non-natural: er…The Myth of Er?
And more general problems with Plato’s account
• Look up the Myth of Er
– How is it that people are able to survive their deaths?
– Why are some people stupid, and others clever?
• Does anything strike you as strange about what
Plato is saying about innate knowledge?
– He introduces a very metaphysical/non-natural
explanation of why we have innate knowledge.
– And: saying it comes from past experience doesn’t
explain how our innate knowledge seems necessary
– (because necessity isn’t found in sensory
experience…)

13. Arguments for Knowledge Innatism 2
Leibniz: Necessity
• Although the senses are necessary for all our actual knowledge, they aren’t
sufficient to provide it all, because the senses never give us anything but instances,
i.e. particular or singular truths. But however many instances confirm a general
truth, they aren’t enough to establish its universal necessity; for it needn’t be the
case that what has happened always will - let alone that it must - happen in the
same way.
• …it appears that necessary truths, such as we find in pure mathematics and
particularly in arithmetic and geometry, must have principles whose proof doesn’t
depend on instances (or, therefore, on the testimony of the senses), even though
without the senses it would never occur to us to think of them. It is important to
respect this distinction between ‘prompted by the senses’ and ‘proved by the
senses’...
• Logic…has many such truths, and so do metaphysics and ethics... the proof of
them can only come from ‘inner principles, which are described as innate. It would
indeed be wrong to think that we can easily read these eternal laws of reason in
the soul…without effort or inquiry;…

14. Arguments for Knowledge Innatism 2
Leibniz: Necessity
• Leibniz reminds us: ‘…we are innate to ourselves, so to
speak.’
• His argument for the existence of innate knowledge is
based on the apparent necessity of such knowledge-
claims.
• In (vague) Standard Form
P1 All sensory truths are contingent.
P2 Yet we know necessary truths.
C So they cannot be derived from the senses.
C2 But must be either innate, or rationally intuited, or
rationally deduced.

15. Locke’s attack on innatism
‘Essay Concerning Human Understanding’ (1690) Book 2
• The attack on innate ideas:
– Book 1 chapter 3 argues that certain paradigmatic candidates for innate ideas
(God, substance, identity) aren’t really innate at all.
• Our possession of these concepts derives from our experience: we reflect
on our experience, and abstract general ideas from it.
– Book 2 presents the positive theory of the origin of our ideas
• Namely Locke’s attempt to show how all the ideas we do in fact have are
explicable in terms of experience.
• Since this theory is simpler and more elegant than the rival theory of
innate ideas, it should replace it. (‘Ockham’s razor’)
• ‘I can show... how men can get all the knowledge they have, and
can arrive at certainty about some things, purely by using their
natural faculties without help from any innate notions or
principles…’

16. Locke’s attack on innatism
‘Essay Concerning Human Understanding’ (1690), Book 1
How does Locke define innate knowledge?
‘certain principles…are accepted by all mankind. Some people have argued
that because these principles are (they think) universally accepted, they must
have been stamped onto the souls of men from the outset.’
His attack on innate knowledge
Locke argues that the innatist faces a dilemma. If innatism means
(a) ‘universal consent’ or that everyone actually has this knowledge at their
fingertips all along  this argument is empirically false, since 1. children
and ‘idiots’ do not have this knowledge. 2. there are many disagreements
in ethics and theology.
(b) ‘the capacity to form knowledge’  trivial as every proposition we come
to know (even those we come to know through experience) is innate in
this sense. Locke thinks that we can’t have unconscious ideas.

17. Other definitions of innateness that Locke
attacks and rejects
• Innateness = ‘by the use of reason men may discover these
principles, and that this is sufficient to prove them innate…all
mathematics must equally count as innate because they can all be
known for certain through the use of reason…We may as well think
that the use of reason is necessary to make our eyes discover
visible objects’ these abstract principles are arrived at by
reflection on experience.
• Innateness = ‘prompt assent given to a proposition upon first
hearing it and understanding the terms…? If so, then we must
classify as innate…various propositions about numbers [and from]
even the natural sciences [such as]: Two bodies cannot be in the
same place at the same time; It is impossible for the same thing to
be and not to be; White is not black; A square is not a circle. Now, I
agree that a proposition is shown to be self-evident by its being
promptly assented to…[but this comes] from a different source
which I shall present in due course’ these abstract principles are
arrived at by reflection on experience.

18. Leibniz’s response to Locke:
the ‘prompted’ vs ‘proved’ distinction
1. We CAN have unconscious ideas. Leibniz says Locke is wrong to claim
that only ideas we are conscious of can be in the mind. His argument
here: we use ‘general principles’ (such as those Locke talks about) which
are relied on constantly by our minds even though we don’t think about
them.
1. So we can know things without being directly conscious of them. (‘tacit knowledge’)
2. We sometimes need assistance to remember things.
3. Locke’s likely reply: we will have learned our tacit knowledge from experience at some
prior point.
2. We know necessary truths, which we can’t derive from experience, as
all experiential truths are contingent. All necessary truths are innate,
therefore. We discover them by examining what is already in the mind.
1. Sense experience is necessary but not sufficient to uncover them.
2. We unconsciously use our knowledge of necessary truths, which then become explicit
through the action of experience on our minds.

19. Leibniz’s response to Locke:
the ‘prompted’ vs ‘proved’ distinction
3. Innate knowledge is a disposition, an aptitude in the mind. Having an
innate idea doesn’t mean we merely have the capacity to form the
concept, but that we have a predisposition for experience to uncover just
that concept and no other (the marble analogy).
1. Experience triggers innate concepts by uncovering them. We then see them to be
true.
2. The potential knowledge of necessary truths is innate, not the actual knowledge.
4. Universal consent isn’t the same as universal knowledge. We have
access to necessary truths which are universal.
1. But our desires conflict with these sometimes.
2. This is why it looks like there isn’t universal agreement.

20. Modern Ideas about ‘triggering’
Or: why innatism is probably correct…
• We now know that many dispositions and capacities are
genetically determined.
• Experience has a role to play, but it triggers the prior
capacity only.
• These capacities ‘come on line’ at specific points in
individual development
– Example 1: birdsong
– Example 2: the ‘Intentional Stance’ in humans
– Example 3: Chomsky’s ‘Poverty of Stimulus’ idea in relation to
language-learning
– Example 4: the notion of ‘Object Permanence’ in babies
• Experience is necessary but not sufficient: it triggers the
acquisition of some knowledge, but is not its source.

21. Reminder:
Arguments against concept innatism
• Are given by concept empiricists such as Locke, Hume, Berkeley
• These arguments also (mostly) apply against knowledge innatism:
– There are no such concepts/no such knowledge and we do not possess them/it –
‘innate concepts’ are ‘empty’, the terms meaningless – ‘From what impressions is
that supposed idea derived?’ - Hume
– Such concepts/knowledge can be re-defined as based on experiences – we can
explain them arguing that they are derived from our experience or learned.
– Locke’s arguments against innatism:
» there is no universal consent/ agreement about such concepts/ knowledge
» It is trivial to say that innate knowledge is just ‘the capacity to know’
» and we can explain how we possess such knowledge in other ways (by
redefining them as based on experience).
– Innatism’s reliance on the non-natural: weird metaphysics (Plato!) or God always
gets invoked to explain where such concepts/knowledge come from.

22. Reminder:
A final argument against concept innatism
Such knowledge is merely analytic
• We acquire such concepts from experience.
• In understanding the concept, we see the necessary truth that
underlies it.
• But all necessary truths are in fact analytic.
• This is why they are self-evident.
• But they are also trivial, because they are merely to do with
definitions.
But! What if…there was synthetic knowledge that was also a
priori?

23. Syllabus moment
Green = we’ve covered this already
• Knowledge empiricism: all synthetic knowledge is a posteriori (Hume’s
‘fork’); all a priori knowledge is (merely) analytic.
• Issues, including:
– knowledge innatism (rationalism): there is at least some innate a priori
knowledge (arguments from Plato and Leibniz)
– knowledge empiricist arguments against knowledge innatism: alternative
explanations (no such knowledge, in fact based on experiences or merely
analytic); Locke’s arguments against innatism; its reliance on the non-natural
– intuition and deduction thesis (rationalism): we can gain synthetic a priori
knowledge through intuition and deduction (Descartes on the existence of
self, God and the external world)
– knowledge empiricist arguments against intuition and deduction: the failure of
the deductions or the analytically true (tautological) nature of the conclusions
– arguments against knowledge empiricism: the limits of empirical knowledge
(Descartes’ sceptical arguments).

24. The opposing view: Rationalism - key doctrines
1. Innatism
– some truths are innate
– some concepts or knowledge are
inherent
2. The Intuition and Deduction Thesis
– other necessary/a priori truths
can be uncovered by the rational
intellect
– Rational intuition and rational
deduction are how the intellect
does this
– Some of this knowledge is of
synthetic a priori truths…

25. What is Rational Intuition?
• Seeing something to be
true ‘in a flash’
• Perhaps seeing it to be true
independently of
experience
• ‘Indubitable rightness’ or
intellectual certainty
• Descartes’ ‘C + D = T’
notion

26. What is Rational Demonstration?
• Seeing something to be true
because
– it follows as a consequence
from other self-evident
truths…
– …which are more basic and
more self-evident
– ‘Inferential chains’ are
formed…
– …as you deduce one certain
truth from another…
Step 1
•God exists
Step 2
•And God isn’t a deceiver
Step 3
•So I can trust my senses
(when they are checked by
my intellect)
Step 4
•They tell me the external
world exists.
Step 5
•And so the external world
does exist!
Descartes: Meditation 6

27. Could there be…
synthetic a priori knowledge?
• Is ‘Hume’s Fork’ correct in analysing ALL knowledge into
two kinds: synthetic a posteriori and analytic a priori
• Much a priori knowledge is analytic or tautologous (and
definitions do serve a purpose, sometimes).
• But some a priori knowledge might not be analytic.
Consider propositions like
– [transcendental/metaphysical] ‘every event has a
cause’
– [logical] ’no object can be red and green all over at
the same time’
– [moral] ‘happiness is an intrinsic good’
• Are these
– True by definition? True because of our sensory experience? or
– Via an act of rational insight…?

28. Kant on “event”
An example of synthetic a priori knowledge
• Kant: some statements are true of experience, but true
independently of experience. Our faculty of rational insight tells us
this.
• For instance, in the proposition “every event has a cause”, “event”
arguably is not defined in terms of “cause”.
– The two words are importantly related, but they are not synonyms.
– One’s knowledge of “events” might arise through experience, but not
derive from it. (Leibniz’s “prompted not proved” idea)
– And one learns something fundamental and very useful about the
world from the proposition.
– And once learned, the truth of the proposition is evident independently
of experience.
– In fact, it is a precondition of our being able to experience at all…
• This kind of knowledge is called by Kant “synthetic a priori
knowledge”
• In this sense, we have innate knowledge of e.g. cause

29. A posteriori A priori
Synthetic True only for now but could be
different. e.g. Chilis are hot,
Speeding is dangerous.
Contingent but useful, ‘vivid’.
Prompted but not proved by
experience. True
independently of experience.
e.g. maths, the Categories
of Kant – Cause, Substance
etc.
Discoverable, useful,
informative, necessary,
Structure our experience of
the world
Analytic ? Null – see Kripke, though... Self-evidently true, necessary,
wholly independent of any
admixture of experience.
Subject contains predicate
e.g. ‘Bachelors are unmarried’
Tautologous. Dull.
Definitional.

30. How can knowledge of the synthetic a priori
be possible?
• Apparent analyticity or logical necessity lets us see the
truth of tautological propositions like “bachelors…”
• But a priori or rational intuition lets us see that, say,
‘happiness is an intrinsic good’
• A priori intuition =
– immediate, non-inferential grasp or apprehension
– “seeing” that an item of knowledge is necessarily true
– not propositional /to do with words
– so unlike beliefs and more like the immediacy of perceptual
sensations
• Kant says that we have a Faculty/Power of the mind for
acquiring this knowledge

31. Why is the synthetic a priori so desirable?
• the apperception of synthetic a priori truths via an act of
intellectual intuition
– gives us the certainty of a priori propositions.
– And gives us useful content in a way that tautologous
or analytic a priori propositions do not.
• Synthetic a priori knowledge, therefore, would be
– True independently of experience, certain
–anduseful, interesting…
• (But can we be confident that intellectual intuition is
always correct?)

32. Cartesian examples: the intuition and
deduction thesis at work
• ‘the apperception of synthetic a priori truths via an act of
intellectual intuition or deduction’
• This description applies to:
• The Cogito (Meditation 2)
• The notion of Clear and Distinct Ideas (Meditation 2)
• The Trademark Argument for the existence of God
(Meditation 3)
• The Ontological Argument for the existence of God
(Meditation 5)
• Descartes’ proof of the existence of the external world
(Meditation 6)

33. Descartes’ proof of the existence of the
external world (Meditation 6)
“If [my ideas of matter] were transmitted from a source other
than corporeal things, God would be a deceiver; and he is not.
So bodies exist. They may not all correspond exactly with my
sensory intake of them, for much of what comes in through the
senses is obscure and confused. But at least bodies have all
the properties that I clearly and distinctly understand, that is,
all that fall within the province of pure mathematics.”
P1 There are two possible sources for the origin of sensation:
God or Matter.
P2 If their origin were in God, God would be a deceiver.
C Their origin is in matter.
P1 God would not allow me to be deceived in judgements
based on clear and distinct ideas.
P2 I have a clear and distinct idea of the geometric and
mathematical properties I perceive in matter.
P3 I have an approximate idea of other properties of matter.
C1 Therefore I can correctly judge that material objects really
possess mathematical and geometric properties.
C2 And I can verify my other perceptions with my rational
intellect.
Step 1
•God exists and isn’t a deceiver
Step 2
• Anything I perceive clearly and
distinctly to be true is true
Step 3
• So I can trust my senses (when
they are checked by my intellect
and shown to be C+D)
Step 4
• They tell me the external world
exists especially with regard to its
geometric properites.
Step 5
• And so the external world does
exist!

34. Knowledge Innatism
knowledge empiricist arguments against intuition and deduction:
• Is the intuition and deduction thesis correct?
• Empiricists reply:
– rational deductions fail and can be misleading
• There are some arguments against the notion of the
infallibility of rational insight (The Monty Hall Problem
etc)
• Many deductive arguments are flawed or inconclusive
– the conclusions drawn using rational deduction
are merely analytically true (tautological)

35. • The Cogito (Meditation 2)
– Does the deduction fail, or is it tautological?
• Think back to the difficulties we raised when
considering the Cogito…
Knowledge Innatism
knowledge empiricist arguments against intuition and deduction:

36. Issues with Descartes’intellectual intuition:
Humean bundles, limited selves
• Can Descartes claim that he has an immediate, unmediated,
non-inferential perception of himself?
• In opposition to Descartes, David Hume says that whenever
he tries to perform the Cogito, he has no certain
consciousness of himself…
– “For my part, when I enter most intimately into what I call myself I
always stumble on some particular perception or other, heat or cold,
light or shade, love or hatred, pain or pleasure. I never can catch
myself at any time without a perception, and never can observe
anything but the perception.” (Treatise, I,iv,6)
• For Hume…the self is just a bundle of sensations
• There isn’t a Cartesian self/’Cartesian Homonculous’ after all…
– Arguably the Cogito is a proof only of flashes of self-existence, at best
– Arguably it does not prove the existence of a classically conceived self
or ego

37. Issues with Descartes’ intellectual intuition:
Lichtenberg, grammar, absence of self
• Compare
– ‘Eric runs’ – there is a subject, running.
– ‘It rains’ – is there a subject, raining?
– ‘Eric thinks’ – there is a subject, thinking.
– ‘I think’ – is there a subject, thinking?
• Georg Lichtenberg (C18 physicist, aphorist): ‘“It thinks”,
we really ought to say, just as we say, “It thunders”’.
• We assume the sentence ‘I think’ has a subject…does it?
• At best, ‘I think’ and ‘I am’ are synonyms: thinking implies
existence, that’s all…

38. • The Ontological Argument for the existence of God (Meditation 5)
– Is the deduction used in the Ontological Argument merely to do with
definitions?
– Is it a flawed deduction?
• The Trademark Argument for the existence of God (Meditation 3)
• Does the deduction fail, or is it tautological?
Knowledge Innatism
knowledge empiricist arguments against intuition and deduction:

39. • This critique of the Trademark Argument is
first given by Descarte’s friend Arnauld.
• Arnauld suggests that the deductive
argument Descartes uses is flawed…
• Here’s what Descartes says…
‘I clearly and distinctly perceive God to exist.’
‘And God guarantees that anything I clearly and
distinctly perceive to be true is true.’
• Anything odd about this argument?
A vicious circle
Knowledge Innatism: The Cartesian Circle
knowledge empiricist arguments against intuition and deduction:

40. • Even if the Cogito is only performed for an instant it is
indubitably true whilst it is being performed.
• It is a ‘clear and distinct idea’:
– “I call 'clear' that perception which is present and manifest to an
attentive mind…”
– I call 'distinct', that perception which, while clear, is so separated and
delineated from all others that it contains absolutely nothing except
what is clear“.
– “If we give assent only to those things which we clearly and distinctly
perceive, we will never accept anything false as being true…”.
• So: C&D = T!
• But: can we be wrong about our intellectual intuitions?
Knowledge Innatism: Clear and Distinct Ideas
knowledge empiricist arguments against intuition and deduction:

41. Epimenides’ Paradox (600 b.c.)
A Cretan tells you: ‘All Cretans are liars’.
A Cretin paradoxThe Cretan paradox
Knowledge Innatism: Confused Intuitions
knowledge empiricist arguments against intuition and deduction:

42. • Zeno’s Paradox: Achilles and the tortoise
• Achilles is in a footrace with the tortoise. He is very fast. The tortoise is
very slow.
• Achilles allows the tortoise a head start (of 100 metres, say).
• The race starts. After some finite time, Achilles will have run 100 metres,
bringing him to the tortoise's starting point.
• But during this time, the tortoise has run a much shorter distance, say, 10
metres.
• It will then take Achilles some further time to run that distance.
• By which time the tortoise will have advanced farther.
• Thus, whenever Achilles reaches somewhere the tortoise has been, he still
has farther to go.
• Therefore, because there are an infinite number of points Achilles must
reach where the tortoise has already been, he can never overtake the
tortoise.
Knowledge Innatism: Confused Intuitions
knowledge empiricist arguments against intuition and deduction:

43. • What’s a paradox?
• A paradox = believing two contradictory propositions
at the same time.
• The logician Willard Van Orman Quine distinguishes:
– Falsidical paradoxes, which are seemingly valid, logical
demonstrations of absurdities – such as Zeno’s paradoxes.
– Veridical paradoxes, such as the Monty Hall paradox,
which are seeming absurdities that are nevertheless true
because they are perfectly logical.
Knowledge Innatism: Confused Intuitions
knowledge empiricist arguments against intuition and deduction:

44. • Descartes’ proof of the existence of the
external world (Meditation 6)
• Does the deduction fail, or is it tautological?
• Does Descartes’ claim that we can at least know the
mathematical qualities of the world convince?
• Is the existence of the material world really a matter of
demonstration in the first place?
Knowledge Innatism
knowledge empiricist arguments against intuition and deduction:

45. • But what of the innatist’s arguments about
the limits of empirical knowledge?
• Consider Descartes’ sceptical arguments in
Meditation One.
• Which are?
Knowledge Innatism
knowledge innatist arguments against empirical knowledge: