5/28/10

Westphal, Jonathan - Review of Roy Sorenson's Seeing Dark Things

05/28/2010

Paper delivered for panel discussion

This is a review of the Roy Sorenson book Seeing Dark Things, which is a book that espouses the causal theory of perception and the nature of shadows and silhouettes. Author takes the opportunity to discuss Sorenson's main points, but also disagrees with them and elaborates his own position in the review.

The first example author discusses is the example of "Near" and "Far", two planets that completely occlude the sun at the exact same time (from the point of view of the Earth). What happens is that the far planet "Far" occludes the sun, and, simultaneously, a closer planet, "Near" also moves into the same exact position that Far occupies in our field of vision. The closest thing to us is the near side of Near. Nevertheless, Sorenson argues that when we see the big black blot in front of the sun, we are seeing the thing that actually causally stops the sun's rays, which is the far side of Far. Author agrees-- though he explains it not as bolstering the causal theory but instead as part of a theory of shade and in describing celestial bodies in 'purely astronomical terms'. Author also worries about what this kind of example might underwrite for the causal theory, that, somehow, we can 'see' the far (obscured) sides of things.

The next discussion can be brought out by the example of a bird flying (and landing) onto the near side of a barn, but coming to rest somewhere in the barn's shadow. The light source is on the other side of the barn and when the bird flies into the shadow it disappears. From this simple case it seems there is an inconsistent triad:

1) If X causes a shadow, then some light is falling directly on X
2) X cannot cast a shadow through an opaque object
3) All shadow is shadow of something

With the bird/barn case, it seems the barn is casting a shadow through the opaque object of the bird, a violation of 2. But then it is clear that the shadow is in the shape of the barn, upholding (sort of) 3. But if we say the barn isn't casting a shadow through the bird, then 1 saddles us with the absurdity that some light is hitting the bird in order to keep the barn-shape of the shadow.

Author makes a comment on the ungrammatical aspects of 3, but first goes about denying the sense of 2 that generates the inconsistency. Author argues for a distinction between the concept of shade and that of shadow. Shade is the lack of illumination, whether partial or complete. Shadow is shade with shape. Shade can be cast through opaque objects, since 'through' isn't being used as a physical-causal term. With this distinction, author examines 3 and concludes that confusing these concepts also contributes to the inconsistency: All shadow is shadow of something: true. All shade is shade of something: true. All shade is the shadow of something: false.

The next matter of consideration is that of silhouettes. Sorenson's example is of a church steeple that is at a distance, set high in the sky against a low sun or other light source. Here all you make out is the silhouette of the steeple. Here author examines Sorenson's argument is that when you see the silhouette, you see the steeple. Author's problem is one of equivocation. Surely the outline of the shape of the steeple is 'seeing' the steeple, but the dark interior is just the shade of the far side of the steeple, which you don't see. Sorenson would argue (given his Near/Far discussion), that you do see the far side of the steeple. Here author and he part ways and it leads to the next example, this time created by the author: the wall. Author argues that a wall that casts a shadow onto the near side of a road is revealing to you a shaded near side, not a causally-efficacious far side. If, for instance, you dropped something valuable on the near side, you would look there for it, not on the other side, where you might 'see' it!

The last part of the review discusses Sorenson's odd claim that shadows can only be dark, not colored. Sorenson creates the concept of "Filtows" to represent colored light. Author is just comfortable saying that shadows can be colored. (Sorenson is worried that things like cathedrals will end up being illuminated by shadow.)

5/21/10

Wilson, Margaret - Objects, Ideas and "Minds": Comments on Spinoza's Theory of Mind

05/21/2010

Ideas and Mechanism: Essays on Early Modern Philosophy Ch 9, Princeton University Press

This paper attempts to show that Spinoza's theory of a human mind isn't close to what we understand a human mind to be, especially something considered in Descartes as a thing capable of conscious representation of objects, real or imaginary. Author begins by contrasting Spinoza's conception of minds with Leibniz's 'complete concept' and Descartes' 'res cognitantes' (thinking things).

The first is Leibniz, who gives metaphysical space between God's ideas of objects and the objects themselves. The complete ideas exist within God, but the objects themselves are God creatures. Further, they could be different, as God could have created a different world. So it is likely that for Leibniz, God has complete ideas of even non-existent entities. (pg127) Spinoza seems at odds with both of these positions: objects are attributes of God, and it is unclear if God has ideas of non-existent objects (of extension). (pg127-8)

Author secondly examines Descartes, acknowledging the common problems with the Cartesian picture. However, some of the intuitions are shared by most: anything that occurs in the mind is, by definition, conscious. Secondly, the mind has the ability to have ideas of many different things, whether imaginary or right-in-front-of-your-eyes (formal). Lastly, the mind is supposed to be a marker for rationality, giving mind-substance to some creatures and not to others. On most of these positions it seems Spinoza also disagrees. Spinoza doesn't exactly have an explicit account of consciousness, but for him the mind has an idea of everything-- everything-- that occurs in its body. Spinoza's mental ideas are also limited to just the things that happen in the body; finally, all extended things are also mental things-- that is there is two attributes to every mode of God's action-- even a stone has some level of mentality. (pg129-130)

Author moves on to consider a defense of Spinoza (in section III), but first levels the primary objection of her paper: Spinoza fails to give an account of human mental representation that is anything like what we consider it to be. The reason is that he is committed to minds being about the bodies whose mode they share, which explodes the concept of mental representation. It is exploded (pg131) by failing to find a sufficient condition for a subset of what is going on in the body to be represented in the mind.

Section III deals with the problem of mental representation of objects-- author believes that for Spinoza a human mind can only represent what is happening in its body. Ok, but how do the representations that we have filter up from our bodies? The rub is that it is obvious that not everything that happens in our bodies is represented in our minds. So where's the difference? Author argues there is not one to be found (pg132).

Section IV is an in-depth analysis of the various texts of Spinoza that commentators have claimed purport to show a distinction between conscious and non-conscious thought. Author argues against this interpretation.

Author concludes that without a sufficient condition for human mental representation (as opposed to representing everything in our body) and without a robust distinction between conscious and non-conscious ideas, Spinoza does not have a theory of mind that captures anything like the human mind.

5/14/10

Donagan, Alan - Spinoza's Dualism

05/14/2010

Ch 7 of The Philosophical Papers of Alan Donagan Vol 1 Historical Understanding and the History of Philosophy, University of Chicago Press

This paper is an attempt to show that, although Spinoza was an avowed monist, many of his positions seemed to embrace much of the dualist belief system and seem at odds with what a fully endorsed monist position might be. Author compares this odd stance with the one of Descartes relative to heliocentrism-- though Descartes avowed to be a geocentrist, many of his other positions would give fellow geocentrists little comfort and were compatible with heliocentrism.

Author believes that 'Spinoza accepted numerous positions that are distinctively dualist' (pg117). The first departure requires some explanation. The standard model for attributes and substance is that a substance has one distinct attribute, and that attribute defines its essence (pg117-8). This is inherited entirely from Descartes (the dualist). And yet Spinoza places two (at least) attributes into the God/Nature, both the attributes of extension and thought. This puzzling move seems to suggest that a substance with two attributes would have two essences. (Yet because a substance with 3 essences would be more complete than one with 2, we know that God's substance must encompass all attributes, all essences pg120). Author claims this is not in fundamental conflict with a dualist like Descartes (pg121-2), especially because it claims (with Descartes) that the two attributes are irreducible to each other.

Author takes an explanatory detour into Spinoza's dual-track attribute theory, where everything extended (in the physical world) has a corresponding mental idea or cognition. E.g. a rock tumbling down a hill also has a corresponding mental aspect. (pg123-5) This is germane because it shows the irreducibility of the one attribute into the other; indeed it seems to reinforce their complete unconnected independence.

Author argues that Spinoza could only reconcile his dualist positions with his explicit monism through the awkward (novel?) adoption of the idea that: two distinct attributes may be found together in the same substance. This awkwardness overturns much of his previous work that generally expressed the theory of one attribute=one essence=one substance.