Technology Rig Some days you wish had never started, then along comes one you hope will never end. Anything can happen in a day.

By substance I understand what is in itself and is conceived through itself, i.e., that whose concept does not require the concept of another thing, from which it must be formed.

By attribute I understand what the intellect perceives of a substance, as constituting its essence.

1. Thought (mind or idea) 
2. Extension (matter occupy space)

particular modifications of substance, i.e., particular things in the world. 

PROP. II. Two substances, whose attributes are different, have nothing in common.

PROP. III. Things which have nothing in common cannot be one the cause of the other.

PROP. V. There cannot exist in the universe two or more substances having the same nature or attribute.

PROP. IV. Two or more distinct things are distinguished one from the other, either by the difference of the attributes of the substances, or by the difference of their modifications.

PROP. VI. One substance cannot be produced by another substance. Corollary.—Hence it follows that a substance cannot be produced by anything external to itself.

PROP. VII. Existence belongs to the nature of substances.

PROP. VIII. Every substance is necessarily infinite.

PROP. XI. God, or substance, consisting of infinite attributes, of which each expresses eternal and infinite essentiality, necessarily exists.

PROP. XII. No attribute of substance can be conceived from which it would follow that substance can be divided.

PROP. XIV. Besides God no substance can be granted or conceived.

PROP. XV. Whatsoever is, is in God, and without God nothing can be, or be conceived.

1. No two substances can share an attribute (from the definition of substance).
2. It is in the nature of substance to exist (from the definition of substance).
3. God exists (from 2 and the definition of God).
4. No other substance than God exists (from 1, 3, and the definition of God).
5. Everything that exists is either God or a mode of God (from 3, 4, and the definition of mode).

1. He bases all his prepositions based on his definitions with no justification for them, an example is "Two substances, whose attributes are different, have nothing in common", this results from his definition of "substance" which Leibniz objected to saying "Let’s grant that two substances cannot share all of their attributes. But suppose that A has attributes X and Y, while B has attributes Y and Z. Then, it seems, we could conceive of A and B as distinct, even though they share an attribute (namely, Y)".
2. His "substance" definition mix between two different concepts, for example a substance is either a building block of the universe like a quark or a super-string or something very different from us so it can't be comprehended by our intellectual like god and mixing between these two concepts in his definition led to the mix between our world or nature or humans and god. 
3. Spinoza's monism supposes that God has infinite attributes including extension? But how can we know if this is true or not? Wittgenstein words ring in my ears now.
4. Men show imperfections, but if they are modes of God, is God imperfect also?

1. It allows Spinoza to avoid the problem of interaction between mind and body, which troubled Descartes in his Meditations on First Philosophy. 
2. Creation for Spinoza is a natural result from god's attributes : "From God’s supreme power, or infinite nature, an infinite number of things – that is, all things have necessarily flowed forth in an infinite number of ways, or always flow from the same necessity; in the same way as from the nature of a triangle it follows from eternity and for eternity, that its three interior angles are equal to two right angles."
3. The world is deterministic as Spinoza puts it, "A thing which has been determined by God to produce an effect cannot render itself undetermined". "Of everything whatsoever a cause or reason must be assigned, either for its existence, or for its non—existence". There is no freedom of the will at all.
4. For Spinoza, our universe (cosmos) is a mode under two attributes of Thought and Extension. God has infinitely many other attributes which are not present in our world and that two attributes known by humans, namely Thought and Extension.
5. Spinoza treats God and nature as indistinguishable, by knowing things as they are we improve our knowledge of God. Seeing that all things are determined by nature to be as they are, we can achieve the rational tranquility that best promotes our happiness, and liberate ourselves from being driven by our passions. Sensory perception, which Spinoza calls "knowledge of the first kind", is entirely inaccurate, since it reflects how our own bodies work more than how things really are. We can also have a kind of accurate knowledge called "knowledge of the second kind", or "reason". This encompasses knowledge of the features common to all things, and includes principles of physics and geometry. We can also have "knowledge of the third kind", or "intuitive knowledge". This is a sort of knowledge that, somehow, relates particular things to the nature of God.
6. A better understanding of his own place in the cosmic system and of the place of all the objects of his likes and dislikes, and his insight into the necessity which rules all things, tend to cure him of his resentments, regrets and disappointments. He grows reconciled to things, and wins peace of mind. In this way reason teaches acquiescence in the universal order, and elevates the mind above the turmoil of passion. The active feelings are all of them forms of self-realisation, of heightened activity, of strength of mind, and are therefore always pleasurable. It is the passive feelings (or "passions") which are responsible for all the ills of life, for they are induced largely by things outside us and frequently cause pain. At the lowest stage of knowledge, that of "opinion", man is under the dominant influence of things outside himself, and so is in the bondage of the passions. At the next stage, the stage of "reason", the characteristic feature of the human mind, its intelligence, asserts itself, and helps to free man from the domination of passions. At the highest stage of knowledge, that of "intuitive knowledge", the mind apprehends all things as expressions of the eternal cosmos. It sees all things in God, and God in all things. It feels itself as part of the eternal order, identifying its thoughts with cosmic thought and its interests with cosmic interests. Thereby it becomes eternal as one of the eternal ideas in which the Attribute Thought expresses itself, and attains to that "blessedness" which "is not the reward of virtue, but virtue itself", that is, the perfect joy which characterises perfect self-activity. This is not an easy or a common achievement. "But", says Spinoza, "everything excellent is as difficult as it is rare."