Abstract:

Historically, Western Epistemology and Metaphysics can be traced as the Realism-Idealism debate.  Metaphysical Idealism is the doctrine that holds non-natural Ideal Substance as Ultimate Reality whereas Metaphysical Realism, being very close with Materialism, conceives all things or this dynamic universe as Real, not illusive.  In Epistemology, Realism-Idealism debate is not equivalent to Metaphysical debate.  Epistemological Realism conceives Known things (external to knower) exist independent of Knower (Mind or Soul) whereas Epistemological Idealism maintains only mental ideas are Real, Known things (as mental idea) does not exist without Knower.

G. E. Moore, a believer of Idealist tradition in his early age, became most critical of Idealism and founder of common sense Realism too.  His doctrine of Realism is Epistemological in nature, he has not challenged the existence of any conscious things, he has not involved in metaphysical debate of ultimate substance, and his endeavor in Philosophy is to prove the independent existence of things that we perceive by common sense.  In other word, his philosophy is also a response to Kantian Agnosticism that believes the things-in-itself are unknowable.

This paper is intended to examine Moore’s Common Sense Realism, as to how he refutes Idealism in order to provide ground for Realism and as to how he proves the existence of Mind independent things by common sense.

Key Words: Common Sense Realism, Idealism, Esse est Percipii, External World, Fallacy of Petito Percipii

Common Sense Realism

Moore is the propounder of Sense data theory. For him, sense data is the source of all kinds of knowledge.  Common sense realism is the doctrine that believes on actual reality of things, which we know as sense data.  Basic notions of common sense realism has been traced in his writing ‘‘Defence of common sense’.  Proof for this has been supplied in his lecture ‘Proof of external world’.

Moore expelled from idealism to realism because of idealist disconnection with ordinary people’s belief.  They use the ambiguous and very intellectual language that is difficult to understand.  They claim the unreality of space-time on which we are living and except which we cannot imagine our existence.  We are flowing with time in every moment but they say the dynamism is unreal.  According to them, whatever we perceive does not exist in reality and it is just apparently real.  In idealists such belief, Moore could not find out his existence too, then he reveals the unimportance of such philosophies.  Moore argues that idealism is inappropriate with our ordinary life and language.  According to Moore, rejecting all our common beliefs makes the life meaningless but he could not be convinced with the meaninglessness of life rather he endeavors to show the meaninglessness of Idealism and all other philosophies that conceives our common sense meaningless.

Common sense is that proposition, which we certainly know.  Moore differentiates the common sense proposition into two types; 1) That basic proposition, which we know certainly without any other proposition, and 2) Those propositions that are based on basic proposition.  In his Article, ‘Defense of common sense’ Moore gives various examples of such propositions.  ‘I know that I have body’ is the basic proposition, which we know certainly, and its rejection makes our life impossible.  This type of proposition is knowable by common sense and no intellectual vague language needed to explain it.  ‘Other people likewise me, also know that they have body’ is the propositiondependent upon basic proposition ‘I know that I have body’.  From these examples, it is clear that Moore is talking about Common Sense belief to those beliefs that are acceptable to all in the ordinary life, which is completely related with our life, which we know certainly, whereof rejection is impossible and so on.

Refutation of Idealism (To be is to Perceive)

In his famous article “Refutation of Idealism”, Moore, very genuinely, criticizes the Idealism for the sake of Common Sense Realism.  He finds Idealism is very broadly developed perspectives, thereof criticizing is not easy. Hence, he looks for the central theme of Idealism by criticizing which whole aspect of Idealism would be criticized.  He finds Berkley’s ‘Esse est Percipii’ as the foundational doctrine of Idealism, that includes all aspects of Idealism.  Its critique fulfills the demand of Realism, and criticizing other Idealist’s doctrine would not be needed.  

Moore’s critique on ‘esse est percipii’ is Analytical rather than substantial. He does not elaborate the feature of ultimate substance.  He is just saying ‘to be’ does not need perception. Anything can be there in the absence of perceiver.  In addition, his Analyticity is ordinary rather than symbolic.  Regarding the sense of understanding given by copula (est), he criticizes as follows:

1. In ordinary sense, use of copula (est) indicates the identical nature of subject (Esse) with Predicate (Percipii).  If Esse (to be) is exactly synonymous with Percipii (to perceive), then Percipii cannot indicate anything, which is not indicated by Esse. Thereby, Percipii become the definition of Esse (even though idealists do not hold it as definition).  As it is definition, result must be opposite of Idealists’ conception, that means ‘being’ is definable as that substance which we perceive.  Here, definitional approach leads to realism[1] because being is equivalent to what is perceived.
2. In another sense, copula (est) indicates the Predicate (Percipii) as part of Subject (Esse).  If Percipii is part of Esse, then whatever we perceive is being but only partially, being is something more than perceived, Perceived is dependent of being, Hence Perceived is not Being.  Hence, this is just opposite to Idealist view of ‘to be is to perceive’.
3. In third sense, Copula indicates the Predicate (percipii) as neither identical to subject nor as part of Subject, rather Predicate may be the necessary character of subject.  For example, esse and percipii is related alike smoke-fire relation.  So long as idealists hold the notion thereunder, then thereon, proposition becomes synthetic, and it seems idealist argue this as necessary relation rather than coincidental.  For a synthetic sentence to be necessary, it needs evidence but nobody has such evidence of something that loosed existence in absence of perception.  Hence, Idealists’ view of world is fallacious.  

Proof for Common Sense Realism

Attempt of proving the existence of external world dates back to Greek Philosophy, even idealist Plato conceived world not as mental idea, Aristotle as a realist was believer of existence of soul independent of world. Descartes, father of modern philosophy conceived world as distinctly separate existence without any relation with mind, he believed on external world as rationally knowable.  Kant also believed on the existence of world independent of Mind as Noumenon (thins- in-itself) but Kant argues that we can know only the mental ideas of external world, real things in itself is unknowable.  

Moore looks on these attempts of history but he finds them very ambiguous and difficult to understand.  According to Moore, existence of external world in philosophical history has been a scandal wherein almost philosophers give their view but no one give appropriate proof. Apart from these attempts, Western philosophy was also suffering from Skepticism, which argues that concrete knowledge of the external world is impossible for human reasoning power.  Idealist and Skeptics did not give importance for proof of things outside of us, but for Moore, that is the fundamental task of philosophy.[2] Moore’s project of rescuing the scandal of external world with appropriate proof can be viewed as the response to such Kantian Agnosticism as well as Skepticism.  In his lecture, Proof of an External World, He argues External World exists and can be known in a very simple way by our common sense.  

Before proving, first he distinguishes the ‘things met with in space’ and ‘things presented in space’. This distinction is to get rid of the philosophical ambiguous phrases.  Former corresponds to the Kantian Noumenon (things-in-itself), later match up with the Kantian Phenomenon (mental idea). Former is external to our mind and later is internal. Moore’s operation is on the former; however, he does also believe in the existence of internal ideas (Private to us; like pleasure and pain).

‘Things met with in space’ is a broad and clear term which includes all type of matter as well as our human body. Moore believed that there is a much simpler proof for the things met with in space. At last of his lecture on proof of external world, he says, “By holding up my two hands, and saying, as I make a certain gesture with the right hand, ‘Here is one hand’, and adding, as I make a certain gesture with the left, ‘and here is another’. And if, by doing this, I have proved ipso facto the existence of external things, you will all see that I can also do it now in numbers of other ways: there is no need to multiply examples. “[3]

Now, let us keep his argument in syllogism,

First Premise (P₁)……..Here is one hand.

Second Premise (P₂)…Here is another hand.

Conclusion (C₁)………… ∴There are at least two hand.

Third Premise (P₃)…….Hands is External things to Mind, met up with in space.

Last Conclusion (C₂)…. ∴There are at least two external things met up with in space.

In this way, Moore proved the existence of external world or things met up with in space. He believes that such proof is easier and better proof than Descartes proof in Meditation and is able to refute all types of Epistemic and Metaphysical Scepticism and Idealism.

But this proof cannot satisfy the existence of things of our memory which we perceived in past. Then he gave second proof based on memory in similar way:

1) I lifted one hands two minutes ago.

2) I lifted another hand two minutes ago.

∴  There have existed at least two hands (Mind independent object) in the past.

By this conclusion, it is obvious to say, Hands might have existed at another time without being perceived, it might have existed at another time without being perceived at other time, during the whole period of time, it need not have been perceived at any time at all.

This second proof is more crucial because it proves the existence of things without being perceived. It fulfills his project of ‘Refutation of Idealism’ and provides solid argument for common sense belief while first argument is just proving the ordinary realism that Mind Independent things exists.

Again, he judged his proof by certain logical criteria that 1) Premise must be different from the conclusion; 2) Premise must be known to be true, 3) Conclusion must be follows from premises. It is obvious that all the premises are different with conclusion and by the simple reasoning; we can judge that the conclusion is drawing from premises and hence criteria first and third satisfies but second criteria is difficult to explain. He argues that premises (for truth) are known by common sense and it is absurd to discard the existence of hands which is connected with our all functioning. Moore raising hand while lecturing in a room is certitude for those who are hearing and seeing him. In this way he satisfies the second criteria.

Fallacy:

Fallacy can be found in Moore’s fulfillment of second criteria in above proof.  His whole project is to prove “Here is a Hand” but he maintains it as true, supposing its truthfulness is knowable by common sense.  Common sense is not a provable matter.  He says it is ipso facto. If it is ipso facto, why he needs to prove it is a crucial question.  In common sense, no one rejects the existence of world surrounding us.  What Idealist and Skeptics challenge to the common sensical world is because of either lack of our knowledge power (as in Kant) or searching an ideal that regulates this dynamic world as its manifestation (as in Berkley).

Moore is proving ‘Here is hand’ (hand; as representation of external world) and again he is assuming this in premise as true and ipso facto.  Taking to be proved thing as ipso facto is the fallacy of petito principii found in his proof of external world.

Conclusion:

Before Moore, No proof had been given to things outside of us and Moore successfully established the proof based on his common sense realism.  In his lecture, ‘Proof of external world’ He concludes two fundamental conclusion that 1) Things outside of our mind exists and 2) there is no need of perceiver for the existence of external things. For him, these two conclusions are sufficient to refute all kinds of Idealism (esse est percipii), and to believe the authenticity of common sense without skeptics.  However, fallacy of petito principii found in his syllogism again faces the skeptical challenge, to which he has not responded, and I think common sense realism is unable to face that challenge.

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[1] As ‘Being’ is equivalent to ‘what is perceived’, things what is perceived must be being-in-itself, and no other thing exists beyond it.  So it leads to metaphysical realism.

[2] Moore, G. E., Proof of External World

[3] Moore, Proof of external world,

Bibliography:

1. Moore, G. E., Defence of Common Sense
2. Moore, G. E., Proof of External World
3. Moore, G. E., Refutation of Idealism