Aim of the
Metaphysics is partly…

§To identify the basic
principles of sensible
entities.

§To then explain by means of
these principles how it is that sensible entities can change.

 

Aristotle begins this
‘metaphysical’ investigation
by pointing out that earlier philosophers regard the topic of
the nature of substance as being the subject matter of metaphysics, (983b, p. 311 bottom).

 

Pre-Socratics identified substance with kinds of matter, such as earth, air, fire and water;

whereas “Present-day thinkers” (i.e., Platonists) identify substance with (ideal) Forms,

since the latter are concerned with what is most real from a theoretical
(not perceptual) point of view.

Aristotle rejects
Plato’s view of Forms

This is because Aristotle
believes that Plato cannot
solve the regress problem
that Plato himself pointed out
his dialogue the Parmenides.

Remember in the
Parmenides, the character Parmenides objects to
Plato’s Forms in the
following way.

You assume, Plato, that
participating in, for example,
the Form of Large explains how all ordinary large things can be large.

But Parmenides
continues (132a-b)…

Suppose you view the
Large itself along with the
common large things. 
Won’t a Large2 appear as
the Form which this collection
has in common?

Why must there be a
further Form of Large,
a Large2?

It is because for Plato if a
group of items have a property
in common, then each item in the group has a share of (participates in) the Form that is that property.

 

So an infinite regress ensues,
since whenever a Form is
“viewed with” the ordinary
objects that “participate in”
the Form, the enlarged group shares
a common feature that must be explained by the fact that each member of the enlarged group shares in a Form of the very same kind.  

A Large3  emerges and
so on to infinity. 

 

Aristotle responds to
the regress problem…

§By rejecting
transcendent Forms.

§By insisting that ordinary
objects are combinations
of form and matter.

 

Aristotle points out,
however, that ordinary
objects are only one kind of substance, namely, what he
calls sensible, perishable substance.

There is also, he believes,
sensible imperishable substance
and immutable (i.e., imperishable, unchangeable) substance.

For example:

1. Humans, dogs, flowers,
etc. are sensible
perishable substances.

2. The heavenly bodies are
sensible imperishable substances.

3. The unmoved mover is a
non-sensible, immutable
(i.e., unchangeable, eternal substance).

We will now concentrate
on his view of sensible, perishable substance.

The most basic explanatory principles
of these ordinary objects
(sensible, perishable substances)
are form and matter.

Sensible, perishable substances are form/matter compounds.

Form/Matter Compounds

 

 

 

 

 

 

 

 

 

 

 

                                               

                                   

                                   

 

 

 

Consider first the (substantial or essential) form.

The substantial or essential form, aka, “essence,” is what makes a thing a member of its natural kind. The essential form is a set of capacities to do certain things.  For example . . .

 

 

 

 

 

 

 

 

 

 

 

                                               

                                   

                                   

 

 

 

 

This bundle of flesh, bones, etc. is essentially a rabbit.

 

To be essentially a rabbit  is to move, grow, perceive, eat, reproduce as a rabbit does.

So Aristotle’s essential form consists of:

§Characteristics/capacities
that make the entity the
type of entity that it is.

§In a living thing, these are the characteristic ways in which members of different species grow, perceive, eat, move, and reproduce.

 

So whereas Plato thinks to be a rabbit is to participate in the Form of Rabbit, Aristotle thinks being a rabbit = having rabbit capacities.

Consider next matter.

Aristotle posits basic matter …

 

 

 

 

 

 

 

 

 

 

 

 

 

                                   

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                                   

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                                   

 

Consider again form.

To complicate matters,
Aristotle also posits what are called accidental forms.

§Accidental forms are characteristics that a sensible entity can gain or lose, have or not have, while still being essentially the kind of sensible entity that it is.

§For example, a  rabbit can be white and then become brown or it can be a white rabbit or be a brown one without ceasing to be a rabbit.

 

Rabbits with different accidental (color) properties.

To even further complicate matters,
Aristotle has in fact
4 different kinds of forms.

§Among the essential forms:

§one is the actual essential form

§Another is the potential essential form.

§Among the accidental forms:

§Many are actually in the sensible entity. These are the actual accidental forms.

§Others are potentially in the sensible entity.  That is, the entity is such that it can acquire these other accidental forms, losing the ones that it now has.

For example, consider
our rabbit again. 
It has the actual, essential
form of being a rabbit. 
It has the potential essential form of being a carcass.  Its actual accidental forms include being healthy, being small, and being white. 
But it has the potential accidental forms of being sick, growing large, and becoming muddy or brown.

 

 

 

To sum up:  Aristotle, like Plato, considers form to be one of the basic principles that “constitutes” or
fundamentally explains how a
a sensible, perishable entity is the kind of entity that it is. 

 

 

So for Aristotle, sensible, perishable entities are form/matter combinations.  But for Aristotle,  contrary to Plato’s view, the form is not outside of space and time but rather is in the matter.     

 

 

 

Now, as we will see in the next class, Aristotle’s idea of
potential form…

Enables him to explain
change in a way that
preserves Parmenides’
dictate, that something
cannot come from nothing.