material objects

material objects

occupy space, persist through time, composed of matter (Newton: matter = mass)

numerical

one and the same

qualitative

same properties

diachronics

same thing over time

simple

a fundamental particle

mereological essentialism

an object cannot survive any change in parts (if you change even one part, it is now a new object)

mereology

the study of how parts and wholes relate

part

something that makes up a hwole

proper part

a part that isn’t identical to the whole

Ship of Theseus

if you replace parts gradually, does it make it the same ship as before?

statue and clay

different modal and temporal properties, possibly distinct objects

problem of the many

if you remove one atom, is it the same object?

option one for Theseus ship

S1=S2, but not S=3: Reparied ship is still the original ship

option two for Theseus ship

S1=S3, but not S2: The ship made from the old planks is still the original

option three for Theseus ship

S1=S2 and S1=S3: Both are the same ship

option four for Theseus ship

neither S2 nor S3 = S1, no ship is the original

nihilism (Unger)

complex objects don’t really exist, only atoms do

maximal property view (Sider)

only the largest complete collection counts as the real object

accept the weirdness

there are many nearly identical objects coexisting

reflexive

x=x

symmetric

if x=y, then y=x

transitive

if x=y and y=z, then x=z

Leibniz’s law

if two things share all properties, they are identical. If two things have different properties, then they are not identical 

special composition question

when do some objects combine to form a new object?

moderate composition

sometimes parts form wholes (common-sense view)

mereological nihilism

no composite objects exist; only time, partless “simples” exist

mereological universalism

any non-overlapping objects compose a new thing 

false positives

touching doesn’t mean a new object is made

false negatives

some composites exist without contact

cohesion

compose if they stick together

fusion

compose if they are fused into one mass

organicism (Van Inwagen)

composition only occurs when the parts constitute a living being