Notes for 10/15/2026

  

10/15/2026

 

[Philosophy Club every Wednesday, 5-6 pm, in the Buchtel College of Arts and Sciences room 436 ("The Cave")

Bioethics Club Tuesdays from 4:30-5:30 in CAS 436.]

 

 

What would YOU think is an example of a substance?

 

 

 

 

Since all ideas ultimately derive from experience, it follows that to really/properly understand our ideas, it is important to trace them back to their experiential origins (this is the “New Way of Ideas”). Conceptual clarification consists in tracing ideas back to their experiential origins. (Allows us to resolve philosophical disputes.)

 

Locke emphasizes the limitations of human knowledge and as a result the necessity of “epistemic humility”.

 

In large part this connects to (and is possibly motivated by) Newton’s approach to physics.

 

Newton introduces the connection between Calculus and physics.

 

 

 

Physics consists in mathematical description of how things behave.

(Sidelining of metaphysics.)

 

 

For example:

 

 

This tells us how gravity BEHAVES, but not what it IS.

 

Locke builds on this: Our senses are incapable of revealing the whole truth about the nature of matter.

 

Therefore, our knowledge of the true/real essences of things is forever limited.

 

 

The key to Descartes’ approach to science was to use V&C perception to ascertain the essences of things.

Locke distinguishes:

 

Nominal essences: Properties things reliably have in our experiences of them. (Basically, appearances.)

 

Real essences: Properties things have objectively and in themselves, whether we can perceive them or not. (Basically, reality.)

 

 

Locke thinks the limitations of our senses render us ineliminably incapable of knowing real essences.

 

 

Cartesian certainly is a lost cause.

 

Epistemic empiricism: The limits of knowledge are defined by what can be learned from experience. (This WILL need some qualification as we go on.)

 

 

 

One of the most important applications of this concerns the concept of substance.

 

 

D, S, & L all ground their metaphysics in substance, and believe reason can reveal the real essences of substances.

 

 

But Locke does not think reason is capable of this (because of his epistemic empiricism).

 

 

The traditional substance metaphysics holds that substances are the bottom level foundation for properties (things that have properties vs properties of things).

 

Sense experience only provides direct knowledge of properties.

 

Substances themselves are never perceived.

 

This means that the idea of substance is an idea of reflection: Properties can’t go marching around the universe without belonging to something.

 

But we only ever perceive the properties. The something they belong to is inferred (pointed to) by reason.

 

What this means is that our idea of substance can never be “vivid and clear”.

 

It is a very abstract idea which is nothing more that whatever it is that properties ultimately belong to (inhere in).

It is a ‘something we know not what’ that supports qualities.

“We have in fact no idea of what substance is, but only a confused obscure one of what it does, namely, it supports accidents.”

 

 

This kills Descartes’ arguments for substance dualism.

 

The idea of mental substance, as such, is exactly the same as the idea of material substance, as such.

 

We can never know whether or not the same substances that support mental properties could also support material properties.

 

 

Locke’s theory of substance has been called the “pin cushion” theory of substance.

 

There are no criteria of differentiation at the level of substance but only at the level of properties.

 

 

 

 

 

Primary-secondary quality distinction in Locke

 

In Descartes, secondary qualities are confused intellections of primary qualities. (They are artifacts of, and exist in, the mind.)

 

In Locke, secondary qualities are powers that objects in the world have in virtue of their primary qualities to affect us in ways that cause certain kinds of ideas. (They exist in the world, not in the mind.)

 

There is a distinction between our IDEAS OF secondary qualities and those qualities THEMSELVES. The qualities themselves are the causal powers inherent in the objects to affect us in certain ways, and the ways they affect us are the ideas we have of these powers.

 

Our ideas of primary qualities RESEMBLE (copy) the qualities in the objects.

 

Our ideas of secondary qualities DO NOT RESEMBLE the qualities in the objects themselves.

 

(Nor do our ideas of TERTIARY qualities resemble qualities in the objects themselves.)

 

What are tertiary qualities? Powers objects have to affect other objects, i.e., causal powers.