Metaphysics in Early Modern Philosophy
The Atomic Theory of Matter The atomic theory poses a challenge to theories of substances or objects Atomic theory: things are composed of atoms; properties of things depend on nature and motion of atoms Things are not as they appear
Appearance and Reality Aristotle: objects cause perceptions, and are represented in them Causes of perception = objects of perception Atomic Theory: No causes are the atoms which are real objects are appearances
Causes and Effects Causes of perception are the atoms We don t see atoms, but their effects What we see doesn t exist in reality How can we distinguish the aspects of the effects (appearances) that do match the causes?
Primary and Secondary Primary qualities: mathematical properties, assigned to atoms by physical theory e.g., size, shape, mass, motion Secondary qualities: effects of primary qualities on us e.g., color, texture, moral and aesthetic qualities
Primary Qualities Descartes: We perceive clearly and distinctly only the mathematical properties of objects: size, shape, motion Only they reflect the true natures of things
Primary Qualities Locke: Primary qualities are inseparable from objects; atoms have them Primary qualities are those objects possess according to the atomic theory of matter They produce simple ideas in us that resemble the primary qualities in the objects
Secondary Qualities Secondary qualities are effects of objects on our nervous systems They produce ideas in us that do NOT resemble them
Secondary Qualities Secondary qualities depend on primary qualities Secondary qualities are response-dependent: to have one is just to produce a certain effect in a (normal) perceiver
Primary and Secondary To be red is just to look red to a standard perceiver in standard conditions
Aristotle on Essence The essence of x = what it is to be x what x is by virtue of itself what x is by its very nature what is expressed by a definition of x (a formula for the nature of x)
Aquinas on Essence The essence of x = the properties necessary to x, without which x would not be what it is The quiddity of x = what corresponds to x s definition in the world The nature of x = what makes x what it is
Aquinas on Essence The essence of wax = the properties necessary to wax, without which wax would not be wax The quiddity of wax = what corresponds to wax s definition in the world The nature of wax = what makes wax what it is
Aquinas on Essence The essence of wax =?? a combination of: The quiddity of wax = compound that is malleable near ambient temperatures The nature of wax = organic compound that consists of long alkyl chains (CnH2n+1 or CnH2n-1).
Real and Nominal Essence Aristotle and Aquinas identify: The essence of x = the properties necessary to x The quiddity of x = the definition of x in re The nature of x = what makes x what it is
Real and Nominal Essence Locke: Nominal essence = quiddity: uses secondary qualities Real essence = nature: real internal constitution
Real and Nominal Essence Gold
Real and Nominal Essence Gold Nominal essence: heavy yellow metal
Real and Nominal Essence Gold Nominal essence: heavy yellow metal Real essence: element with atomic number 79
Real and Nominal Essence Water
Real and Nominal Essence Water Nominal essence: colorless, tasteless liquid (at common temperatures) necessary to life
Real and Nominal Essence Water Nominal essence: colorless, tasteless liquid (at common temperatures) necessary to life Real essence: H 2 O
Elms and Beeches Same nominal essence: North American deciduous tree?
Elms and Beeches Different real essences: Ulmus Americana and Fagus Grandifolia
Real Essences Aristotle and Aquinas: We know objects by grasping their essences Locke: Which essence? Nominal: concept; secondary qualities; conditioned; so, mind-dependent Real: real internal constitution; primary qualities; unconditioned; so, mind-independent
Categorematic Terms means, connotes Triangle Essence: Triangularity Daniel refers to, denotes A triangle
Categorematic Terms Which essence? means, connotes Triangle Essence: Triangularity Daniel refers to, denotes A triangle
Natural Kind Terms means, connotes Elm Essence: Being an elm Daniel refers to, denotes An elm
Natural Kind Terms Which essence? means, connotes Elm Essence: Being an elm Daniel refers to, denotes An elm
Natural Kind Terms means, connotes Elm Nominal Essence: NA deciduous tree Daniel refers to, denotes An elm
Natural Kind Terms means, connotes Elm Real Essence: Ulmus Americana Daniel refers to, denotes An elm