What is this thing called Metaphysics?

Brian Garrett

• Éditeur: Routledge
• Année: 2017
• ISBN:
  9781317565963
• Édition: 3
• Sujet: Philosophy
• Sous-sujet: Philosophy History & Theory

How did our universe come to be? Does God exist? Does time flow? What are we? Do we have free will? What is truth? Metaphysics is concerned with the nature of ourselves and the world around us. This clear and accessible introduction covers the central topics in metaphysics in a concise but comprehensive way. Brian Garrett discusses the crucial concepts and arguments of metaphysics in a highly readable manner. He addresses the following key areas of metaphysics:

• God

• Existence

• Modality

• Universals and particulars

• Facts

• Causation

• Time

• Puzzles of material constitution

• Free will & determinism

• Fatalism

• Personal identity

• Truth

This third edition has been thoroughly revised. Most chapters include new and updated material, and there are now two chapters devoted to attacks on free will and fatalism.

What is this thing called Metaphysics? contains many helpful student-friendly features, such as a glossary of important terms, study questions, annotated further reading, and a guide to web resources. Text boxes provide bite-sized summaries of key concepts and major philosophers, and clear and interesting examples are used throughout.

1
• god

• INTRODUCTION

One of the oldest metaphysical questions is: does God exist? In discussing this question, we understand ‘God’ in the standard philosophical sense of a necessary being who created and sustains the contingent universe of space and time. Such a being is traditionally regarded as all powerful (omnipotent), all knowing (omniscient) and wholly good (omnibenevolent).

In this chapter, we examine and criticize the three best known philosophical arguments for God’s existence. These are known as the Ontological, Cosmological and Teleological arguments, and each has different versions.

The versions of the Ontological and Cosmological Arguments presented here purport to be deductively valid arguments. The Teleological Argument, in contrast, is an inductive argument of the type known as ‘inference to the best explanation’. (Some versions of the Cosmological Argument are also of this type.)

A further difference between the arguments is that the premises of the Ontological Argument are a priori true (if true), whereas the Cosmological and Teleological Arguments employ contingent, empirically true premises (viz. that the spatio-temporal universe exists, and that the world contains complex biological structures).

• THE ONTOLOGICAL ARGUMENT

There have been many different versions of the Ontological Argument throughout the history of philosophy, but the first, and most discussed, is that presented in the eleventh century by St Anselm, Archbishop of Canterbury, in his Proslogion. Here is a crucial paragraph from which we can reconstruct his argument:

Thus even the fool is convinced that something than which nothing greater can be conceived is in the understanding, since when he hears this, he understands it; and whatever is understood is in the understanding. And certainly that than which a greater cannot be conceived cannot be in the understanding alone. For if it is … in the understanding alone, it can be conceived to exist in reality also, which is greater. Thus if that than which a greater cannot be conceived is in the understanding alone, then that than which a greater cannot be conceived is itself that than which a greater can be conceived. But surely this cannot be. Thus without doubt something than which a greater cannot be conceived exists, both in the understanding and reality.¹

A reconstruction might proceed as follows:

(1) The idea of God is the idea of that than which nothing greater can be conceived.

(2) Since we grasp the idea of God, God exists in the understanding.

(3) God either exists in the understanding alone or exists both in the understanding and in reality.

(4) It is greater to exist in the understanding and in reality than to exist in the understanding alone.

(5) If God exists in the understanding alone, a greater being could be conceived – namely, a being with all God’s qualities who exists both in the understanding and in reality.

(6) So God cannot exist in the understanding alone (from 1 and 5).

(7) So God exists both in the understanding and in reality (from 3 and 6).

(8) So God exists (in reality) (from 7).

Premise (1) is intended to be true by definition. According to Anselm, the word ‘God’ simply means ‘that than which no greater can be conceived’, just as ‘triangle’ means ‘three-sided plane figure’ or ‘bachelor’ means ‘unmarried man’. So the fool could no more sensibly deny that God is that than which nothing greater can be conceived than he could sensibly deny that triangles are three-sided or bachelors unmarried.

Premises (2) and (3) are also intended to be truistic. According to Anselm, to conceive of F is for F to exist in the understanding. And for any F that has been conceived, either F exists in the understanding alone or F exists both in the understanding and in reality. For example, unicorns and dragons exist in the understanding alone; men and horses exist both in the understanding and in reality.

Premise (4) is motivated by the following train of thought. Suppose we consider two beings alike in all their properties, except only that the first exists in the understanding alone, while the second exists both in the understanding and in reality. Then the second being is greater than the first. Given (1)–(5), (8) quickly follows.

Note that if Anselm’s proof is sound, we can use similar reasoning to prove that God exists necessarily:

(i) God exists (i.e. (8)).

(ii) If God exists contingently, a greater being could be conceived – namely, a being with God’s defining qualities who exists necessarily.

But:

(iii) God is that than which nothing greater can be conceived.

Therefore:

(iv) God exists necessarily.

St Anselm (1033–1109)

Anselm was born in Aosta in Italy. He became a monk and was later appointed Archbishop of Canterbury. As much a theologian as a philosopher, Anselm is credited with putting forward the first version of the Ontological Argument for God’s existence. Anselm’s belief in God did not rest on his proof. He simply wanted to make manifest God’s essence (which is to exist). His Ontological Argument has had a mixed reception: Aquinas and Kant rejected it; Duns Scotus and Descartes proposed their own versions of it. Although the argument has few adherents today, there is no consensus on where the reasoning goes astray.

Criticizing Anselm’s proof

Questioning premise (1)

Might we object to Anselm’s definition of God? Here are two objections.

(i) Not all definitions are coherent. For example, I might try to define ‘meganumber’ thus:

(M) The meganumber is that natural number than which there is no larger.

But (M) is incoherent. There is no largest natural number since the natural number series is infinite.

Is there any reason to think that Anselm’s definition (premise (1)) is similarly incoherent? There will be if God’s great-making qualities are non-maximal (i.e. qualities which can always be possessed to a greater degree, such as height or weight). However, it is arguable that God’s great-making qualities – omnipotence, omniscience and perfect goodness – are maximal. No being can be more powerful than an all powerful being or morally better than a perfectly good being. So we cannot criticize Anselm’s definition of God as we did definition (M).

(ii) Even so, could there not be two or more beings than which no greater can be conceived? Perhaps, for any conceivable being we can always conceive of another equally great one. Anselm assumes that there is exactly one being than which no greater can be conceived, but this assumption of uniqueness needs to be justified. (Does omnipotence raise a complication here? Could there be a world with two or more omnipotent beings? Yes, provided ‘omnipotent being’ is taken to imply only ‘being than which no other is more powerful’ and not ‘the most powerful being’.)

Questioning premises (2)–(5)

What of the next few steps in Anselm’s reasoning? In premises (2)–(5) Anselm presupposes a quite bizarre account of what it is to understand a word. The opening three sentences in our quote suggest the following chain of thought. I understand a word ‘F’ (a general term, say, such as ‘unicorn’ or ‘horse’) and thereby grasp the concept of an F. In virtue of grasping the concept, an F exists in my understanding and has the qualities typical of an F. We can then inquire whether Fs also exist in reality.

Thus, when I understand the word ‘unicorn’, a unicorn exists in my understanding and has the qualities typically associated with unicorns (four legs, spiral horn, lion’s tail, etc.). But this is incredible. When I understand the word ‘unicorn’, I do not have something four-legged and spiral-horned in my mind. Anselm has committed what we might call the fallacy of reification. He has confused the mind’s grasping a concept (for example, the concept unicorn) with the mind’s containing an instance of that concept (an individual unicorn).

In other words, Anselm is supposing that if I possess the concept of a unicorn, then a unicorn exists – if only in my mind. But this is a mistake. Though I possess the concept of a unicorn, unicorns do not exist (in the mind or in reality). Neither unicorns nor horses exist in the understanding, though our concepts or ideas of them do. It follows that there cannot be ‘two beings alike in all their properties, except only that the first exists in the understanding alone, while the second exists both in the understanding and in reality’.

Premises (2)–(5) commit the fallacy of reification. Once we recognize that it is a fallacy – that when I understand the word ‘God’ there is not something in my mind which is omnipotent, omniscient, etc. – we must reject those premises. They are based on an untenable construal of what it is to grasp a concept.

Summing up

St Anselm’s Ontological Argument is a classic example of a rationalist argument. His argument attempts to show that we can establish a substantial conclusion – God’s existence – by reason alone. This contradicts the empiricist principle (associated with philosophers such as Locke, Berkeley and Hume) that reason alone can never produce knowledge of reality. Empiricists hold that knowledge of reality relies essentially on input from one or more of the five senses.

The Ontological Argument is ingenious. It attempts to prove the existence of God merely from the idea or definition of God as ‘that than which no greater can be conceived’. It would be extraordinary if the definition of a word could prove the existence of anything beyond itself. Fortunately, it does not.

The parody of Gaunilo the monk

Although the above suffices to dispose of Anselm’s version of the Ontological Argument, it is worth discussing a response made to Anselm by one of his contemporaries, the eleventh-century Benedictine monk Gaunilo of Marmoutiers. Gaunilo famously proposed a parody of Anselm’s Ontological Argument for God’s existence. In ‘A Reply on Behalf of the Fool’ Gaunilo recalls the legend of an island ‘with all manner of priceless riches and delights in abundance’, more excellent than any other conceivable island. He continues:

You cannot any more doubt that this island that is more excellent than all other islands truly exists somewhere in reality than you can doubt that it is in your mind; and since it is more excellent to exist not only in the mind alone but also in reality, therefore it must needs be that it exists. For if it did not exist, any other island existing in reality would be more excellent than it, and so this i...