A. Some features of Spinoza's metaphysical system and his Ethics.
Spinoza's system is the paradigm of a rationalist system, for it clearly maintains the superiority of reason over the senses, rejects brute facts (vs. Descartes), and attempts a strictly deductivist approach to knowledge.  It is also the most famous version of pantheism and rejection of the personal God of the three religions (vs. Descartes): God, in Spinoza's view is nothing but Nature operating on the basis of its own metaphysically necessary laws. The outcome is a form of radical naturalism (vs. Descartes).
The Ethica Ordine Geometrico Demonstrata has the 5 parts:
1. On God
2. On the nature and origin of the mind
3. On the nature and origin of the emotions
4. On human bondage, or the strength of the emotions
5. On the power of the intellect, or of human freedom.
Here we study part 1 and sections of part 2.

B.  Ordine geometrico demonstrata: the Ethics adopts a strictly deductivist procedure, showing Euclid's influence.  The definitions are supposed to be real, not nominal, definitions (similar to  Socratic definitions).  However, they are often obscure.  The axioms often suffer from the same defect.  Perhaps, S. believed that the truth of the conclusions justifies the axioms and definitions.  The proofs are a mixed bag; some are problematic, as they rely on unclear axioms and definitions.

Part I: God

Devoted to an analysis of the nature of God and the main outlines of its relation to the world.  Can be divided into 4 sections:
1) Definitions & axioms.
2) Props. 1-15 : the essence of God.
3) Props. 16-29: divine power and the casual system rooted in it.
4) Props. 30-6 plus appendix: theological consequences of first two parts.

A. Definitions and Axioms

Definitions
Def. 1: X is self-caused just in case X's essence involves existence
Def. 2: X is finite in its own kind if it can be limited by another thing of the same nature (e.g. a body by another body).
Def. 3: "By substance I mean that which is in itself, and is conceived through itself: in other words, that of which a conception can be formed independently of any other conception."

• D's view of substance in the Principles (I,51-2): Substance is that which is causally self sufficient.
• Since the idea of self-inherence seems absurd, "what is in itself" is best understood in terms of causation, as meaning "that which is self- caused".  However, this is a controversial point.
• Hence, substance has two main features:
1. Ontological independence (causa sui)
2. Epistemological independence (conceived, i.e. understood, through itself)

• examples: D's extension and thought.
• S. identifies attribute and substance (e.g. at IP4d).  Probably this is to be understood  in the Cartesian sense that an attribute is distinguishable from its substance only by a distinction of reason. In other words, attribute and substance differ as  adjectival and  substantival presentation of the same content.  This seems to do justice to S' claim that "each attribute of one substance must be conceived through itself" IP10.

Problem: Substance has infinite attributes. Is S. consistent?
Reply: Different perspectives of the same thing, like the concave and convex aspects of a curve.

• Modes are caused by, are ways of being of, and are understood through, their substance.
• Analogue of substance/mode: law of a series and specific values of it plus the idea that the values are produced by the law of the series itself.

Def. 7: Being free is being self-caused and self-determined; being constrained is being other-caused and other-determined.

Def. 8: "By eternity I mean existence itself, insofar as it is conceived necessarily to follow solely from the definition of that which is eternal."
NOTE:There are 3 main views of eternity:

1. Eternity  as necessary existence
2. Eternity as sempiternity
3. Eternity as a-temporal existence

NOTE: (1) is compatible with (3) and, with some effort, with (2).

Axioms

Ax.1: "Everything which exists, exists either in itself or in something else."
This says that everything is either a substance or a mode.
Ax.2: "That which cannot be conceived through anything else must be conceived through itself."
This says that everything is intelligible.
Ax.3: "From a given definite cause an effect follows necessarily; and on the other hand, if no definite cause be granted, it is impossible that an effect can follow."
This amounts to saying that:

• Causes necessitate, i.e. conflation of causal and logical necessity. An effect follows from its cause as the Pythagorean theorem from the nature of right triangle.
• Nothing happens without a cause.

NOTE: So, S. adopts the strongest possible version of the Principle of Suffient Reason (PSR)

• This amounts to saying that if X causes Y, then Y can be fully understood only through X, and that if Y can be fully understood only though X, then X causes Y.
• For S, as for Aristotle or Hobbes, to know fully is to know  through causes; for example, knowing a mathematical theorem involves knowing its  proof.

B. The Essence of God (props. 1-15)

Prop 1: Substance is ontologically and epistemologically prior to its modes..
Prop 2: Two substances with different attributes have nothing in common because they can be conceived independetly of each other.
Prop 3: Two things which have nothing in common are causally idependent of each other (from Ax. 5-4)
Prop 4: "two or more things are distinguished one from the other either by the difference of the attributes of the substances, or by the difference of their modification."
The demonstration amounts to claiming that since all there is is substances and their modes, things can be distinguished from each other only by reference to substances (here identified with their attributes), or modes.
Prop 5: "There cannot exist in the universe two or more substances having the same nature or attributes."

• this is one of the most important props in the first part because it is used to prove S's pantheism.
• the proof falls into 3 parts:
1. if several distinct substances be granted, they must be distinguished either because of their attributes or because of their  modes (because of prop (4)).
2. If the former case, then no two have the same attributes.

Problem: Suppose two substances, A and B such that A has attributes x, y and B has attribute x.  Then, they would be distinct because of their attributes, and yet they would share an attribute, namely x (Leibniz's objection)
Replies:
• Substances, a la Descartes, can have only one attribute.  However, this reply won't do because God has an infinity of attributes
• A substance is to be identified with each of its attributes.  So, attributes x and y are the same thing, namely A; that is, x and y are A described in different ways.
This leaves the case in which substances could differ because they have different modes, as D would say minds differ. S tries to eliminate this possibility as follows:
3. If the latter case, then "as substance is prior to its modes (prop 1), it follows that setting the modes aside, and considering substance in itself, that is, truly, (def. 3 & 6), there cannot be conceived one substance distinct from another, that is (by prop 4), there cannot be granted several substances, but one substance only."

Problem: Why should one be entitled to "set the modes aside" simply because substance is prior to its modes?
Replies:
• If two substances A and B differ only because of their  modes, since modes are accidental, they could have the same modes. But they would still be different substances (they would still be two). Hence, they are not distinguished by their modes. That is, if A and B are distinct, they are necessarily so, but it is contingent that they have different modes. Hence, the latter cannot be the reason of the former.

NOTE: this involves denying the Identity of Idiscernibles.
• Modes cannot distinguish substances because often they can be distinguished from each other only by assuming that they belong to different substances (Think about identical qualities in two substances: they are distinct qualities not because they 'look' different, but because they belong to two different substances.

• PSR assumed.
• In note II to prop 8, S claims that prop (7) is self-evident if one thinks about it. (He also goes on to show that there is only one substance-the 20 men proof)

• S claims this follows from def. 4, but unclear why.  The idea perhaps is that the more reality a thing has, the more ways of looking at it there are.
• In prop 10 note, S implicitly criticizes Descartes: although each attribute is conceived through itself, it is clear that Prop. 9 is true. In particular, an absolutely infinite being must have infinite attributes.

NOTE: Rejection of eminential attribution

• The idea of the proof simple: God necessarily exists and has all the attributes (prop 11, def. 6). But there cannot be two substances with the same attributes (prop. 5). Hence God's necessary existence precludes that of any other substance. It also precludes the possibility of any other substance, for a possible substance must exist (prop. 7).
• This is S's extreme monism : prop 11  says that God exists necessarily; prop 14 says that God is the only possible substance.
• Corollary 2 states that the extended thing and the thinking thing are either attributes or modes of God.

1. God is not to be understood anthropomorphically.
2. It cannot be claimed, with Descartes, that God created extended substance because:
• No substance can be produced by anything else
• One cannot explain how an incorporeal God can create matter.
3. There is no problem in claiming that God is infinitely extended because substance is not made up of parts, and all the objections against infinite extension assume it has constituent parts.

NOTE: Cardinality arguments against actual infinity and standard answer in terms of totum analyticum.
4. Moreover, even if extension had parts, it would not detract from God's power, since nothing can act on God.

The second part of Ethics Part I is devoted to the treatment of:

• God as the self-sufficient source of things and their intelligibility (props. 16-20)
• The system of particular things produced and conceived through  their source, God. (props. 21-29)

• In corollary 2, S notes that God is the only free cause.
• In the note, he makes two main points:
1. God is omnipotent because everything conceivable flows from its nature like geometrical properties flow from the nature of triangle.
2. If God has an intellect and a will, they must differ from ours as the dog in the sky and that in the yard because God is the cause both of the existence and of the essence of humans (ultimately, for S God has no will and, as natura naturans, no understanding either).

NOTE: Contrast with Aquinas' analogical approach and leibniz's partly univocal approach.

1. God is the immanent (not the transitive) cause of things because they can be conceived and exist only through God
2. God, i.e. all the attributes, are eternal and, viewed as natura naturans, unchangeable.

At this point S passes to the analysis of the modal system  and in effect he provides his counterpart of the orthodox doctrine of the derivation of the world from God, creation from nothing, by adopting his own version of emanation.

Props 21-2: these deal with eternal and infinite modes, i.e., modes which follow from God's attributes: some follow immediately from divine attributes and can be viewed as "immediate" modes; others follow from ""immediate" modes, and can be viewed as "mediate" modes. An example of the former in the attribute of extension is motion-rest (letter 64); an example of the latter in the attribute of extension is "the face of the whole universe" (letter 64)

•  Proofs are very unclear
•  One can view immediate infinite modes as basic ways of existence of God as extended (e.g., the physical world as endowed with motion/rest), and mediate infinite modes as the laws embedded in, and following from, the immediate infinite modes (e.g., the conservation of mv).
• More generally, one can say that the immediate infinite modes in extension are the basic features of physical reality, e.g., motion, rest, force, etc., and the mediate infinite modes are the laws of     nature stemming from them, e.g., the law of universal gravity., the law of falling bodies etc.
• Notice that S modifies Descartes' view of extension by deriving from it motion/rest, i.e., introducing dynamical elements in it.

• a finite chain of infinite terms (the infinite modes ending in divine attributes)
• an infinite chain of finite terms (other finite modes).

NOTE: Not clear whether reply is satisfactory.

C. Theological consequences (props 30-36 & appendix)
 
Props 30-31: the intellect, finite or infinite, must comprehend God and its modes, since there is nothing else. That is, the object of the understanding is God.  Moreover, understanding, will, love, desire, etc., being a modifications of thought, belong to God as modalized, i.e., as natura naturata.
Prop 32: the will cannot be called a free cause, but only a necessary cause, because it is but a mode of thought and hence it is determined like everything else.
Corollary 1: God, as a substance (natura naturans) has no will, i.e., has no volitions, and hence no free will.  Same for understanding.  Their relation to the attribute of thought is the same motion/rest has to that of extension. So, God is not a person for S. (Deus sive Natura).
Prop 33: Things could not have been brought about by God in any manner or in any order different from that which has in fact obtained.

• The proof : if the prop. were false, then God's nature could have been different. But by prop. 11, such a nature would exist. Hence, there would be two substances, which cannot be.
• In Note 1, S. claims that what we call "contingent" is fully determined and is so called just because we ignore its necessary causes. Contingency is a name for our ignorance.
• In note 2, S. argues that the traditional view that God chooses by  "free will" to create this world but could have chosen otherwise is incompatible with divine perfection as understood by the very same theologians who attribute free will to God.

1. why people believe in final causes
2. why it is wrong to believe in them
3. how the belief in final causes has bad consequences, being the source of many errors.

2. Why teleology is wrong:

• part I of the Ethics shows that causality is efficient, not final.
• the notion of a final cause turns "Nature completely upside down, for it regards as an effect that which is in fact a cause, and vice versa."
• assumes that God needs something, since he acts with an end in sight.
• ultimately final causes explain nothing and reduce all things to the will of God, i.e., to ignorance (Example of the falling stone  killing  someone). This method of reasoning apparent when people talk  about parts of the human body and appeal to a designer.

NOTE: S. attacks the role of power seeking clergy in upholding miracles.